Analysis for buckling and vibrations of composite stiffened shells and plates

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结构力学（structuralmechanics）

结构力学（structural mechanics）Structural mechanics is a branch of solid mechanics, which mainly studies the laws of force and force transfer of engineering structures, and how to optimize the structure. The so-called engineering structure refers to the system that can bear and transfer the external load, including the rod, plate, shell and their combinations, such as aircraft fuselage and wing, bridge, roof truss and load-bearing wall.The task is to study structural mechanics in engineering structure under external load stress, strain and displacement law; analysis of different forms and different materials of engineering structure, analysis method and calculation formula for engineering design; engineering structure subjected to external forces and transfer; research and development of new engineering structure.The natural structure observed in nature, such as roots, stems and leaves of plants, animal bones, egg shell, can find their strength and stiffness related not only to material, but also closely related with their shape, many engineering structures are natural structures created out of inspiration. The structure design should not only consider the strength and stiffness of the structure, but also to do material saving and light weight. The weight is particularly important for some projects, such as aircraft weight can make the aircraft flight range, rising quickly, high speed and low energy consumption.A brief history of structural mechanicsHumans began to manufacture all kinds of artifacts in ancienttimes, such as houses, boats and bow, musical instruments, these are simple structure. With the progress of society, people for structural design patterns and the strength and stiffness of the structure has been gradually recognized, and accumulated experience, which is reflected in the brilliant achievements of ancient buildings, such as Egypt, Pyramid, China the Great Wall, Zhaozhou Anji bridge, Beijing the Imperial Palace. Despite the presence of mechanics in these structures in knowledge, but did not form a discipline.As far as the basic principles and methods are concerned, structural mechanics is developed simultaneously with theoretical mechanics and material mechanics. Therefore, structural mechanics is integrated with theoretical mechanics and material mechanics in the initial stage of development. By the early nineteenth Century, due to the development of industry, people began to design a variety of large-scale engineering structures, the design of these structures should be more accurate analysis and calculation. Therefore, the analysis theory and analysis method of engineering structure began to be independent. By the middle of the nineteenth Century, structural mechanics began to become an independent discipline.Many computational theories and methods of structural mechanics appeared in the nineteenth Century. At France in 1826 proposed a normal method for solving statically indeterminate structure problems. From 1830s onwards, due to the bridge by train, not only need to consider the bridge under static load problems, must also be considered to withstand the dynamic load, because the bridge span increases, the metal truss structure.In the decades since 1847, scholars have studied the force analysis of statically determinate truss structures by means of graphic method and analytic method, which laid the foundation of truss theory. In 1864, Maxwell established the unit load method and the displacement reciprocal theorem, and calculated the displacement of the truss by the unit load method. Thus, scholars finally got the method to understand the statically indeterminate problem.After the establishment of the basic theory, the new structure and its corresponding theory have been continuously developed while solving the problems of the original structure. From the late nineteenth Century to the early twentieth Century, scholars carried out a lot of mechanical research on the ship structure, and studied the dynamic theory of the beam under the moving load, as well as the problems of free vibration and forced vibration.In the early twentieth Century, the development of Aeronautical Engineering promoted the stress and deformation analysis of thin-walled structures and stiffened plates and shells, and studied the stability problems. At the same time, bridges and buildings started to use a large number of reinforced concrete materials, this requires scientists to study systematically the steel structure, the displacement method was founded in Germany in 1914 of the Dixon, for solving the problem of rigid frame and continuous beam etc.. Later, in the 20~30 century, some simple calculation methods were put forward for the complex statically indeterminate bar structures, so that the general designers could master and use them.By 1920s, people have put forward the idea of honeycomb sandwich structure. According to the concept of limit state of structure, scholars have come up with a new design and calculation theory for beams, plates and frames on elastic foundations. The mechanical problems of structures subjected to various dynamic loads (especially the action of earthquakes) have been studied in many aspects, such as experiment and theory. With the development of structural mechanics, fatigue problems, fracture problems and composite structure problems have entered the field of structural mechanics.In the middle of the twentieth Century, the advent of electronic computers and finite element methods made it possible to make complex calculations of large structures, thus bringing the level of research and application of structural mechanics to a new level.The discipline system of structural mechanicsThe general structural mechanics according to the different nature and its research object is the static structure, structural dynamics, theory, structure, fracture and fatigue theory of rod structure theory, theory of thin-walled structure and overall structure theory etc..Structural statics is the first branch of structural mechanics. It mainly studies the elastic-plastic deformation and stress state of engineering structures under static loads, and the structural optimization problems. Static load refers to the load that does not change with time, the load that changesslowly, and also can be regarded as static load approximately. Structural statics is the basis of other branches of structural mechanics.Structural dynamics is a branch of study on the response and performance of engineering structures under dynamic loads. Dynamic load refers to the load that changes with time. Under dynamic load, the stress, strain and displacement in the structure must be the function of time. Because of the time factor, the research content of structural dynamics is generally more complex than that of structural statics.The theory of structural stability is the branch of study on the stability of Engineering structures. Slender and thin structures are widely used in modern engineering, such as thin rods, thin plates and thin shells. When they are compressed, they will lose stability (wrinkling or buckling) when the internal stress is less than the yield limit, that is to say, the structure produces too large deformation, thus reducing and even completely losing the bearing capacity. Large deformation also affects other requirements of structural design, such as aerodynamic performance of aircraft. The most important content of structural stability theory is to determine the critical buckling load of structures.Structural fracture and fatigue theory is the study of engineering structures are inevitable because of internal crack, crack under external load expansion caused by fracture, caused by fatigue failure would be expanded subject in smaller amplitude under alternating load. Now, the research history of fracture and fatigue is not long and imperfect, but the theoryof fracture and fatigue is developing very fast.In structural mechanics, theoretical and experimental studies on various engineering structures, based on the research object also formed some research fields, which are the main truss structure theory, the theory of thin-walled structures and the overall structure of the theory of three categories. The whole structure is made of raw materials, machined by mechanical milling or by chemical etching. It is especially suitable for some boundary conditions and is often used as variable thickness structure. With the development of science and technology, many new structures emerge, such as sandwich structure and composite structure appearing in the middle of twentieth Century.The research methods of structural mechanics mainly include three kinds of analysis, experimental research, theoretical analysis and calculation of Engineering structure. In the structural design and research, these three aspects are often alternate and complement each other.The use analysis is in the structure use process, carries on the analysis, the comparison and the summary to the structure appears, this is easy and reliable one kind of research method. The use analysis plays an important role in the evaluation and improvement of structure. The newly designed structures also need to be used to test the performance.The experimental research can provide an important basis for the identification of structure, which is also the main means to test and develop the theory and calculation method ofstructural mechanics. The experimental research can be divided into three types: model experiment, real structural component experiment and real structure experiment. For example,Aircraft ground failure test, flight test and vehicle collision test, etc..The mechanical structure usually takes more manpower, material and financial resources, so only to a limited degree, especially in the early stages of the structural design, generally rely on theoretical analysis and calculation of the structural components.In the field of solid mechanics, provides the basic knowledge necessary for the development of material mechanics, structural mechanics, elastic mechanics and plastic mechanics is the theoretical basis of structural mechanics, structural mechanics is also combined with other physical disciplines form many interdisciplinary, such as fluid elastic force etc..Structural mechanics is an ancient discipline, and it is also a rapidly developing subject. A large number of new engineering materials and new engineering structures have provided new research contents and new requirements for structural mechanics. The development of computer provides a powerful computational tool for structural mechanics. On the other hand, structural mechanics also plays an important role in the development of mathematics and other subjects. The emergence and development of the finite element method is closely related to the study of structural mechanics.。

钢结构图纸英文版深化技术规范

1486.1 STEEL STRUCTURES DESIGN AND DRAWINGL T P3 1 3 RATIONALEThis subject is an applied engineering subject. Diploma holders in Civil Engineering willbe required to supervise steel construction and fabrication. He may also be required to design simple structural elements, make changes in design depending upon availability of materials. He must be able to read and interpret structural drawings of different elements.This subject thus deals with elementary design principles as per BIS code of practice BIS:800 and their relevant drawingsDETAILED CONTENTSa) Theory1. Structural Steel and Sections: (2 hrs)1.1 Properties of structural steel as per BIS Codes1.2 Designation of structural steel sections as per BIS handbook and BIS:8002. Structural Steel and Connections: (12 hrs)2.1 Riveted connections, types of rivets, permissible stresses in rivets as perBIS:800, types of riveted joints, specifications as per BIS 800 for rivetedjoints, design of riveted joints for axially loaded members, testing andinspection of riveted joints as per BIS:8002.2 Welded connections: Types of welds, permissible stresses in welds, typesof welded connections, design of butt and fillet welded connectionssubjected to axial loads, testing and inspection of welded joints as perBIS:800hrs) Members: (63. TensionPermissible stresses in tension for steel, design of tension members as perBIS:800 (flats, angles and tee sections only).4. Compression Members: (10 hrs)4.1 Concept of buckling of columns, effective length and slenderness ratio,permissible stresses in compression as per IS:800, strength of columns ofsingle and built up sections with the help of table of permissiblecompressive stresses.1494.2 IS specifications for design of compression members, design of angle,struts and axially loaded columns (no built up columns); use of tackingrivets4.3 Beam and column, frame and seated connections (no design)5. Beams (8 hrs)BIS specifications for the design of simply supported steel beams including design of base plate at the ends (laterally restrained beams only), structural behaviour, deflected shapes and function of various elements of a plate girder and freehand sketching of a plate girder and its elements.6. Roof Truss (10 hrs)Form of trusses, pitch of roof truss, spacing of trusses, spacing of purlins, connection between purlin and roof covering, joint details of roof trusses, loading for roof truss, weight of roof truss, wind loads, snow loads, combination of loads, design of various elements of trussb) Steel Structures Drawing1. Preparation of a working drawing (elevation, plan, details of joints as ridge,eaves and other connections) for a riveted steel roof truss resting on a masonry wall with the given span, shape of the truss and the design data regarding the size of the members and the connections. Also calculate the quantity of steel for the truss.2. Steel connections (a,b,c,d) rivetted and (e) welded all unstiffened- Beam to beam connections (Seated and framed)- Beam to column (Seated and framed)- Column base connections (Slab base, grillage base andgussetted base)- Details of column splices- Connections of a steel bracket with flange of a column3. Detailed drawing showing plan and elevation for a riveted plate girder with thegiven design data regarding the sizes of its parts, with details at the supports and connections of stiffeners, flange angles and cover plates with the web INSTRUCTIONAL STRATEGYTeachers are expected to give simple problems for designing various steel structural members. For creating comprehension of the subject, teachers may prepare tutorial sheets, which may be given to the students for solving. It would be advantageous if150 students are taken at construction site to show fabrication and erection of steel structures. Practice of reading structural drawings is another important feature of this course.RECOMMENDED BOOKS1. Arya, AS and Ajmani, JL; "Design of Steel Structures", Roorkee, Nem Chandand Bros.2. Ram Chandra, "Design of Steel Structures", Delhi, Standard PublishersDistributors.3. Duggal SK, "Design of Steel Structures", Standard Publishers Distributors.4. Kazimi and. Jindal, “Design of Steel Structures”, Prentice Hall of India, NewDelhi5. LS Negi, ‘Design of Steel Structure”, Tata McGraw Hill, New Delhi1516.2 EARTHQUAKE RESISTANT BUILDING CONSTRUCTIONL T P3 - - RATIONALDiploma holders in civil engineering have to supervise construction of various earthquake resistant buildings. Therefore, the students should have requisite knowledge regarding terminology of earthquake and the precautions to be taken while constructing earthquake resistant buildingsDETAILED CONTENTS1. Introduction to Seismic Design Parameters (10 hrs)1.1 Introduction to Earthquakes1.2 Causes of earthquakesHypocenter1.3 Epicenter,1.4 Earthquake waves: Primary waves, secondary waves, long waves1.5 Seismic Region: Seismic zones in India1.6 Intensity and is isoseismal of an earthquake1.7 Magnitude and energy of earthquakehrs)(2 2. Performance of buildings under pastearthquakes3. Introduction to provisions of IS: 1893:2002 (4 hrs)4. Introduction to ductile detailing provisions of IS:13920 for Reinforcedhrs)(6ConcreteBuildings5. Introduction to IS:4326 for construction of earthquake resistant masonry buildings(6 hrs)6. Special construction methodologies, tips and precautions to be observed whileplanning, designing and construction of earthquake resistant buildings(8 hrs)hrs) Management (6 7. DisasterDisaster rescue, psychology of rescue, rescue workers, rescue plan, rescue bysteps, rescue equipment, safety in rescue operations, debris clearance andcasualty management152 INSTRUCTIONAL STRATEGYThe student may be taken for visit to various building construction sites where precautions related to earthquake resistant construction are being taken so that the students may appreciate the importance of the subject.RECOMMENDED BOOKS1. Elements of Earthquake Engineering by Jai Krishana and AR Chandersekaran;Sarita Parkashan, Meerut.2. Building Construction by BL Gupta and NL Arora, Satya Prakashan, New Delhi3. Manual Published by Earthquake Engineering department, IIT Roorkee1893-20024. IS139205. IS43266. IS1536.3 COMPUTER APPLICATIONS IN CIVIL ENGINEERING - IIL T P- - 3 RATIONALEComputers play a very vital role in present day life, more so, in all the professional life of engineering. In order to enable the students use the computers effectively in problemsolving, this course offers various engineering applications of computers in civil engineering.DETAILED CONTENTS1. Estimate and costing by the use of software Civil-Prothe project using Primaveraof2. Networkingtechniques3. Introduction and use of software like Auto Survey, Auto Read, Auto Water4. Introduction and use of software for regarding structural analysis and design ofbuildings1546.4 TENDERING AND VALUATIONL T P2 2 - RATIONALEA good percentage of diploma engineers start working as small contractors. They requirethe knowledge of contractorship and associated skills like estimating and costing, tendering and preparation of specifications for various types of jobs. Also diploma holders adopt valuers as their profession. To promote entrepreneurship amongst these engineers, knowledge and associated skills in above field becomes essential . Hence this subject is of great importance to diploma engineers.DETAILED CONTENTS1. Contractorship (8 hrs)- Meaning of contract- Qualities of a good contractor and their qualifications- Essentials of a contract- Types of contracts, their advantages, dis-advantages and suitability, system of payment- Single and two cover-bids; tender, tender forms and documents, tender notice, submission of tender and deposit of earnest money, security deposit, retentionmoney, maintenance period- Types of contracting firms/construction companies2. Preparation of Tender Document (12 hrs)- Exercises on writing specifications of different types of building works from excavation to foundations, superstructure and finishing operation- Exercises on preparing tender documents for the followinga) Earth workb) Masonry worksc) Construction of a small house as per given drawingd) RCC workse) Pointing, plastering and flooring155f) White-washing, distempering and paintingg) Wood work including polishingh) Sanitary and water supply installationsi) False ceiling, aluminium (glazed) partitioning of tile flooringj) Construction of an Industrial shed3. Preparation of tender documents for: ( 6 hrs)- Highways- Culverts- Layout of sewer lines4. Exercises on preparation of comparative statements for item rate contract(2 hrs)5. Valuation (4 hrs)a) Purpose of valuation, principles of valuationb) Definition of various terms related to valuation like depreciation, sinkingfund, salvage and scrap value, market value, fair rent, year’s purchase etc.c) Methods of valuation (i) replacement cost method (ii) rental returnmethodRECOMMENDED BOOKS1. Pasrija, HD; Arora, CL and S. Inderjit Singh, “Estimating, Costing and Valuation(Civil)”, Delhi, New Asian Publishers2. Rangwala, BS; Estimating and Costing”. Anand, Charotar Book Stall3. Kohli, D; and Kohli, RC; “A Text Book on Estimating and Costing (Civil) withDrawings”, Ambala Ramesh Publications4. Chakraborti, M; “Estimating, Costing and Specification in Civil Engineering”,Calcutta5. Dutta, BN; “Estimating and Costing6. STAAD – Research Engineers - USA1566.5 CONSTRUCTION MANAGEMENT AND ACCOUNTSL T P4 - - RATIONALEThis is an applied engineering subject. The subject aims at imparting basic knowledge about construction planning and management, site organisation, construction labour, control of work progress, inspection and quality control, accidents and safety and heavy construction equipment.DETAILED CONTENTSTHEORYCONSTRUCTION MANAGEMENT:hrs) 1. Introduction: (61.1 Significance of construction management1.2 Main objectives of construction management1.3 Functions of construction management, planning, organising, staffing,directing, controlling and coordinating, meaning of each of these withrespect to construction job.1.4 Classification of construction into light, heavy and industrial construction1.5 Stages in construction from conception to completion1.6 The construction team: owner, engineer and contractors, their functionsand inter-relationship1.7 Resources for construction industry: Men, machines, materials and money.2. Construction Planning: (8 hrs)2.1 Importance of construction planning2.2 Developing work break down structure for construction works2.3 Stages of construction planning- Pre-tender stage- Contract stage1572.4 Scheduling construction works by bar charts- Preparation of bar charts for simple construction work- Preparation of schedules for labour, materials, machinery andfinances for small works- Limitations of bar charts2.5 Scheduling by network techniques- Introduction to network techniques; PERT and CPM, differencesbetween PERT and CPM terminology- Developing CPM networks- Analysis of CPM networks, determining completion time,identifying critical activities and critical path, floats etc.3. Organization:(4 hrs)3.1 Types of organizations: Line, line and staff, functional and theircharacteristics3.2 Principles of organisation (only meaning and significance of thefollowing)- Span of control- Delegation of authority- Ultimate responsibility- Unity of command- Jobdefinition(4hrs) Organization:4. Site4.1 Factors influencing selection and design of temporary services for aconstruction4.2 Principle of storing and stacking materials at site4.3 Location of equipment4.4 Preparation of actual job layout for a building4.5 Organizing labour at site158hrs)(7Labour:5. Construction5.1 Conditions of construction workers in India, wages paid to workers5.2 Trade Unions connected with construction industry5.3 Important provisions of the following Acts:- Trade Union Act 1926 (as amended)- Labour Welfare Fund Act 1936 (as amended)- Payment of Wages Act 1936 (as amended)- Minimum Wages Act 1948 (as amended)- Workman Compensation Act 1923 (as amended)- Contract Labour (Regulation and Abolition)Act 1970 (as amended)hrs) Progress: (4of6. Control6.1 Methods of recording progress6.2 Analysis of progress6.3 Taking corrective actions keeping head office informed6.4 Cost time optimization for simple jobs - Direct and indirect cost, variationwith time, cost optimization7. Inspection and Quality Control: (6 hrs)7.1 Need for inspection and quality control7.2 Principles of inspection7.3 Major items in construction job requiring quality control7.4 Stages of inspection and quality control for- Earth work- Masonry- RCC- Sanitary and water supply services- Electrical services159hrs) 8. Accidents and Safety in Construction: (6causes–8.1 Accidents8.2 Safety measures for- Excavation work- Drilling and blasting- Hot bituminous works- Scaffolding, ladders, form work- Demolitions8.3 Safety campaignCONSTRUCTION EQUIPMENThrs) 9. Introduction:(4Construction economy: Factors affecting the selection of construction equipment,rolling resistance, effect of grade on required tractive effort, effect of altitude andtemperature on the performance of internal combustion engines, drawbar pull,rimpull, and acceleration10. Earth Moving Equipment: (7 hrs)Crawler and wheel tractors: their functions, types and specifications, gradability;bull dozers and their use, tractors pulled scrapers, their sizes and output; effect ofgrade and rolling resistance on the output of tractor pulled scrapers, earth loaders,placing and compacting earth fills.Power shovels: Functions, selection, sizes, shovel dimensions and clearances,output; Draglines: Functions, types, sizes, output; clamshells; safe liftingcapacities and working ranges of cranes; hoes, trenching machines: types andproduction ratesACCOUNTS11.ACCOUNTS: (8hrs) WORKPUBLICIntroduction, accounts, work- major, repair, administrative approval –expenditure, Technical sanction, allotment of funds, bill, contractor ledger,Running and final account bills complete, completion certificate & report, handreceipt, establishment-permanent, temporary-aquittance roll. WC, Establishment,MR labour, casual labour roll-duties and responsibility of different cadres,160 budget-stores, returns, direct material, road metal return, account of stock, misc.P.W. advances T & P – verification, survey , returns, account- expenditure & revenue head, remittance and deposit head, cash book, imprest account, temp advance, treasury challan.INSTRUCTIONAL STRATEGYThis is highly practice-based course and efforts should be made to relate process of teaching with direct experiences at work sites. Participation of students should be encouraged in imparting knowledge about this subject. To achieve this objective the students should be taken to different work sites for clear conception of particular topics, such as site organization, inspection of works at various stages of construction and working of earth moving equipmentRECOMMENDED BOOKS1. Shrinath, LS, "PERT and CPM - Principles and Applications", New Delhi, EastWest Press2. Harpal Singh, "Construction Management and Accounts", New Delhi, TataMcGraw Hill Publishing Company.3. Peurifoy, RL, "Construction Planning, Equipment and Methods" Tokyo, McGrawHill4. Wakhlo, ON; "Civil Engineering Management", New Delhi Light and LifePublishers5. Verma, Mahesh; "Construction Equipment and its Planning and Application6. Dharwadker, PP; "Management in Construction Industry", New Delhi, Oxfordand IBH Publishing Company.7. Gahlot PS; Dhir, BM; "Construction Planning and Management", Wiley EasternLimited, New Delhi8. MS Project – Microsoft USA9. Primavera1616.6 ENTREPRENEURSHIP DEVELOPMENT AND MANAGEMENTL T P3 - - RATIONALEEntrepreneurship Development and Management is one of the core competencies of technical human resource. Creating awareness regarding entrepreneurial traits, entrepreneurial support system, opportunity identification, project report preparation and understanding of legal and managerial aspects can be helpful in motivating technical/ vocational stream students to start their own small scale business/enterprise. Based on the broad competencies listed above, following detailed contents are arrived to develop the stated competencies.DETAILED CONTENTS(1) Entrepreneurship (4 hrs)1.1 Concept/Meaning1.2 Needof an entrepreneur1.3 Competencies/qualitieshrs)System (6 (2)SupportEntrepreneurial2.1 District Industry Centres (DICs)Banks2.2 Commercial2.3 State Financial Corporations2.4 Small Industries Service Institutes (SISIs), Small Industries DevelopmentBank of India (SIDBI), National Bank for Agriculture and RuralDevelopment (NABARD), National Small Industries Corporation (NSIC)and other relevant institutions/organizations at State level(3) Market Survey and Opportunity Identification (Business Planning) (6 hrs)3.1 How to start a small scale industry3.2 Procedures for registration of small scale industry3.3 List of items reserved for exclusive manufacture in small scale industry3.4 Assessment of demand and supply in potential areas of growthopportunitybusiness3.5 Understandingin product selection3.6 Considerations3.7 Data collection for setting up small ventures(6Preparationhrs) ProjectReport(4)4.1 Preliminary Project Report4.2 Techno-Economic feasibility report162Viability4.3 Project(5) Managerial Aspects of Small Business (8 hrs)5.1 Principles of Management (Definition, functions of management vizplanning, organisation, coordination and control5.2 Operational Aspects of Production5.3 Basic principles of financial managementTechniques5.4 Marketing5.5 Personnel and Inventory Management5.6 Importance of Communication in business(6) Legal Aspects of Small Business (6 hrs)6.1 Elementary knowledge of Income Tax, Sales Tax, Patent Rules, ExciseRules6.2 Factory Act and Payment of Wages Acthrs) considerations (6 Environmental(7)7.1 Concept of ecology and environment7.2 Factors contributing to Air, Water, Noise pollution7.3 Air, water and noise pollution standards and control7.4 Personal Protection Equipment (PPEs) for safety at work placeshrs) Miscellaneous (6 (8)8.1 Human and Industrial Relations8.2 Human relations and performance in organization8.3 Industrial relations and disputes8.4 Relations with subordinates, peers and superiors8.5 LabourWelfare8.6 Workers participation in managementRECOMMENDED BOOKS1. A Handbook of Entrepreneurship, Edited by BS Rathore and Dr JS Saini; AapgaPublications, Panchkula (Haryana)2. Entrepreneurship Development by CB Gupta and P Srinivasan, Sultan Chand andSons, New Delhi3. Environmental Engineering and Management by Suresh K Dhamija, SK Katariaand Sons, New Delhi1634. Sharma BR, Environmental and Pollution Awareness : Satya Prakashan , NewDelhi5. Thakur Kailash, Environmental Protection Law and policy in India: Deep andDeep Publications, New Delhi6. Handbook of Small Scale Industry by PM Bhandari7. Marketing Management by Philip Kotler, Prentice Hall of India, New Delhi8. Total Quality Management by Dr DD Sharma, Sultan Chand and Sons, NewDelhi9. Principles of Management by Philip Kotler TEE Publication1646.7ELECTIVES6.7.1REPAIR AND MAINTENANCE OF BUILDINGSL T P3 - - RATIONALEOne of the major concerns of a civil engineer is to take care of the building works, already constructed, in order to keep these buildings in utmost workable conditions. Usually it is being felt that the buildings deteriorate faster for want of care and proper maintenance. The buildings usually have a shabby appearance due to cracks, leakagefrom the roofs and sanitary/water supply fittings. Thus the need for teaching the subject isproper perspective has arisen making students aware of importance of maintenance of buildings.DETAILED CONTENTShrs) Maintenance (61. Needfor1.1 Importance and significance of repair and maintenance of buildings1.2 Meaning of maintenance1.3 Objectivesmaintenanceofrepair and maintenancetheinfluencing1.4 Factors2. Agencies Causing Deterioration (Sources, Causes, Effects) (6 hrs)2.1 Definition of deterioration/decay2.2 Factors causing deterioration, their classification2.2.1 Human factors causing deterioration2.2.2 Chemical factors causing deterioration2.2.3 Environmental conditions causing deterioration2.2.4 Miscellaneous factors2.3 Effects of various agencies of deterioration on various building materialsi.e. bricks, timber, concrete, paints, metals, plastics3. Maintenance Management (Principles, inspections, Practices) (6 hrs)3.1 Importance of maintenance management3.2 Organisational structure for maintennce1653.3 Building inspections and reports3.4 Maintenance budgets and estimates3.5 Specifications for maintenance jobshrs) 4. Investigation and Diagnosis ofDefects (6approach/procedure of investigation4.1 Systematic4.2 Objectives of investigation of building defects4.3 Sequence of detailed steps for diagnosis of building defects/problems4.4 Various tests for correct diagnosis of building defects4.5 Various tests on materials for investigatng defects4.6 List non-destructive tests on building elements and materials to evaluatethe condition of the building and study of three most commonly used testscauses (6hrs)root5. Defectsandtheir5.1 Define defects in buildingsclassification of defectsandimportance5.2 Describe5.3 Main causes of building defects5.4 List three main defects and their main causes in various building elements5.4.1 Foundations, basements and DPC5.4.2 Walls5.4.3 Column and Beams5.4.4 Roof and Terraces5.4.5 Joinery5.4.6 Decorative and protective finishes5.4.7 Services5.5 Defects caused by dampness(6hrs)andprotection6. Materials for Repair, maintenance6.1 Basic characteristics of repair materials6.2 Compatibility aspects of repair materials166typesof repair materialsvarious6.3 List6.4 State characteristics of:6.4.1 Anti corrosion coatings6.4.2 Adhesives/bonding aids6.4.3 Repair mortars6.4.4 Curing compounds6.4.5 Joints sealants6.4.6 Waterproofing systems for roofs6.4.7 Protective coatings6.5 Selection procedure of repair materials for specific job7. Remedial Measures for Building Defects (12 hrs)considerations7.1 Preventivemaintenance7.2 Precautions during repair and maintenance7.3 Surface preparation for repairmethodsrepair7.4 Crack7.4.1 Epoxy injection7.4.2 Grooving and sealing7.4.3 Stitching7.4.4 Adding reinforcement and grouting7.4.5 Flexible sealing by sealant7.5 Repair of surface defects of concrete7.5.1 Bug holes7.5.2 Form tie holes7.5.3 Honey comb and larger voids7.6 Repair of corrosion in RCC elements7.6.1 Steps in repairing7.6.2 Prevention of corrosion in reinforcement7.7 Material placement techniques with sketches7.7.1 Pneumatically applied (The gunite techniques)7.7.2 Open top placement7.7.3 Pouring from the top to repair bottom face7.7.4 Birds month7.7.5 Dry packing7.7.6 Form and pump7.7.7 Preplaced – aggregate concrete7.7.8 Trowel applied method1677.8 Repair of DPC against Rising Dampness7.8.1 Physical methods7.8.2 Electrical methods7.8.3 Chemical methods7.9 Repair of walls7.9.1 Repair of mortar joints against leakage7.9.2 Efflorescence removal7.10 Waterproofing of wet areas and roofs7.10.1 Water proofing of wet areas7.10.2 Water proofing of flat RCC roofs7.10.3 Various water proofing systems and their characteristics7.11 Repair of joints in buildings7.11.1 Sealing of joints7.11.2 Types of sealant and their characteristics7.12 Repair and maintenance of public health Services7.12.1 Low pressure7.12.2 Cisterns defects, blocked drains, damaged china ware7.12.3 Maintenance of GI Pipes7.12.4 Repair of traps7.12.5 Repair of overhead and underground water tanks INSTRUCTIONAL STRATEGYThis is very important course and efforts should be made to find damaged/defective work spots and students should be asked to think about rectifying/finding solution to the problem. Visits to work site, where repair and maintenance activities are in progress can be very useful to students.RECOMMENDED BOOKS1. Nayak, BS; "Maintenance Engineering for Civil Engineers", Khanna Publishers,Delhi2. Ransom, WH; "Building Failures - Diagnosis and Avoidance", Publishing E andF.N. Span3. Hutchinson, BD;etc, "Maintenance and Repair of Buildings", Published byNewness - Butterworth1686.7.2 ENVIRONMENTAL ENGINEERINGL T P3 - - RATIONALECivil Engineering diploma holders must have the knowledge of different types of environmental aspects due to development activities so that they may help in maintainingthe ecological balance and control pollution. They should also be aware of the environmental laws for effectively combating environmental pollution. The class room instructions should be supplemented by field visits to show the pollution caused by urbanization and the combatment measures being adopted at site. Extension lectures by experts may be encouraged.DETAILED CONTENTS1. Environment and Ecology (4 hrs)Definition and understanding of environment and ecology concept, ecosystem andtypes of ecosystems, energy flow in an ecosystem, food chain, ecologicalpyramids, consortium and ecological balance, important biogeo chemical andmaterial cycles, (water, carbon, sulphur, oxygen and nitrogen etc)2. Protection of Environment (2 hrs)Importance of clean environment, control of environmental pollution with respectto air, land and water. Conservation of natural resources, environmentaleducation and awareness3. Water Pollution (8 hrs)Causes of pollution in surface and underground water; BIS standards for waterquality, preventive measures to control water pollution, harmful effects ofdomestic wastes and industrial effluent, BIS standards for waste water disposal,measures to combat pollution due to waste water, eutrophication of lakesPollution (6hrs) 4. AirDefinition, principal air pollutants, atmospheric parameters influencing airpollution, types of air contaminants and their sources, effects of air pollution onhuman beings, plants, animals and economic effects, automobile pollution, BISambient air quality standards and measures to combat air pollution。

211063695_内置L-CFRST_十字形短柱耐火性能有限元分析

２０２３年３月第３９卷第２期㊀沈阳建筑大学学报(自然科学版)ＪｏｕｒｎａｌｏｆＳｈｅｎｙａｎｇＪｉａｎｚｈｕＵｎｉｖｅｒｓｉｔｙ(ＮａｔｕｒａｌＳｃｉｅｎｃｅ)㊀Ｍａｒ.㊀２０２３Ｖｏｌ.３９ꎬＮｏ.２㊀㊀收稿日期:２０２２－０９－２５基金项目:国家重点研发计划项目(２０１９ＹＦＣ１５０９３０４)作者简介:陈海彬(１９７３ )ꎬ男ꎬ教授ꎬ博士ꎬ主要从事工程结构抗震㊁防灾减灾工程等方面研究ꎮ文章编号:２０９５－１９２２(２０２３)０２－０２３４－０９ｄｏｉ:１０.１１７１７/ｊ.ｉｓｓｎ:２０９５－１９２２.２０２３.０２.０６内置Ｌ￣ＣＦＲＳＴ十字形短柱耐火性能有限元分析陈海彬１ꎬ曹伟越１ꎬ刘伟浩１ꎬ刘海扬１ꎬ周中一２(１华北理工大学建筑工程学院ꎬ河北唐山０６３０２１ꎻ２中国地震局工程力学研究所地震工程与工程振动重点试验室ꎬ黑龙江哈尔滨１５００８０)摘㊀要目的研究内置格构式圆钢管混凝土十字形短柱四处阴角受火下轴压耐火性能ꎮ方法基于ＡＢＡＱＵＳ有限元软件建立８１种不同工况的耐火极限模型ꎬ分析火灾荷载比㊁钢管内混凝土强度㊁含钢率和钢管强度对耐火极限的影响变化规律ꎬ通过正交试验分析得出不同因素对耐火极限的敏感程度ꎬ最后提出试件耐火极限简化计算公式ꎮ结果试件耐火极限随火灾荷载比增加呈负相关并且显著降低ꎬ其他影响因素均呈正相关ꎬ钢管强度对耐火极限影响程度最低ꎻ耐火极限理论计算结果与有限元结果符合较好ꎮ结论钢管的约束效应对于试件耐火极限有一定影响ꎬ在工程设计时尽量保证约束效应系数大于１１２ꎻ选用火灾荷载比为０４㊁钢管内混凝土强度为６０ＭＰａ㊁含钢率为００６７９㊁钢管强度为３９０ＭＰａ的组合耐火性能最好ꎮ关键词格构式钢管混凝土ꎻ异形柱ꎻ火灾ꎻ有限元分析ꎻ耐火极限中图分类号ＴＵ３９８㊀㊀㊀文献标志码Ａ㊀㊀㊀ＦｉｒｅＲｅｓｉｓｔａｎｃｅＰｅｒｆｒｏｍａｎｃｅＦｉｎｉｔｅＥｌｅｍｅｎｔＡｎａｌｙｓｉｓｏｆＣｒｏｓｓ￣ＳｈａｐｅｄＳｈｏｒｔＣｏｌｕｍｎｓｗｉｔｈＢｕｉｌｔ￣ｉｎＬ￣ＣＦＲＳＴＣＨＥＮＨａｉｂｉｎ１ꎬＣＡＯＷｅｉｙｕｅ１ꎬＬＩＵＷｅｉｈａｏ１ꎬＬＩＵＨａｉｙａｎｇ１ꎬＺＨＯＵＺｈｏｎｇｙｉ２(１ＣｏｌｌｅｇｅｏｆＣｉｖｉｌａｎｄＡｒｃｈｉｔｅｃｔｕｒａｌＥｎｇｉｎｅｅｒｉｎｇꎬＮｏｒｔｈＣｈｉｎａＵｎｉｖｅｒｓｉｔｙｏｆＳｃｉｅｎｃｅａｎｄＴｅｃｈｎｏｌｏｇｙꎬＴａｎｇｓｈａｎꎬＣｈｉｎａꎬ０６３０２１ꎻ２ＫｅｙＬａｂｏｒａｔｏｒｙｏｆＥａｒｔｈｑｕａｋｅＥｎｇｉｎｅｅｒｉｎｇａｎｄＥｎｇｉｎｅｅｒｉｎｇＶｉｂｒａｔｉｏｎꎬＩｎｓｔｉｔｕｔｅｏｆＥｎｇｉｎｅｅｒｉｎｇＭｅｃｈａｎｉｃｓꎬＣｈｉｎａＥａｒｔｈｑｕａｋｅＡｄｍｉｎｉｓｔｒａｔｉｏｎꎬＨａｒｂｉｎꎬＣｈｉｎａꎬ１５００８０)Ａｂｓｔｒａｃｔ:Ｔｏｓｔｕｄｙｔｈｅａｘｉａｌｃｏｍｐｒｅｓｓｉｏｎｆｉｒｅｒｅｓｉｓｔａｎｃｅｕｎｄｅｒｆｉｒｅｉｎｆｏｕｒｓｈａｄｅｄｃｏｒｎｅｒｓｏｆｃｒｏｓｓ￣ｓｈａｐｅｄｓｈｏｒｔｃｏｌｕｍｎｓｗｉｔｈｂｕｉｌｔ￣ｉｎｌａｔｔｉｃｅｃｉｒｃｕｌａｒｃｏｎｃｒｅｔｅ￣ｆｉｌｌｅｄｓｔｅｅｌｔｕｂｅꎬｔｈｅｆｉｒｅｒｅｓｉｓｔａｎｃｅｌｉｍｉｔｍｏｄｅｌｕｎｄｅｒ８１ｄｉｆｆｅｒｅｎｔｗｏｒｋｉｎｇｃｏｎｄｉｔｉｏｎｓｗａｓｅｓｔａｂｌｉｓｈｅｄｂａｓｅｄｏｎＡＢＡＱＵＳｆｉｎｉｔｅｅｌｅｍｅｎｔ第２期陈海彬等:内置Ｌ￣ＣＦＲＳＴ十字形短柱耐火性能有限元分析２３５㊀ｓｏｆｔｗａｒｅ.Ｔｈｅｃｈａｎｇｉｎｇｌａｗｏｆｆｉｒｅｒｅｓｉｓｔａｎｃｅｌｉｍｉｔｗａｓａｎａｌｙｚｅｄｏｎｉｎｆｌｕｅｎｃｉｎｇｆａｃｔｏｒｓꎬｓｕｃｈａｓｔｈｅｌｏａｄｒａｔｉｏꎬｃｏｎｃｒｅｔｅｓｔｒｅｎｇｔｈｗｉｔｈｉｎｔｈｅｓｔｅｅｌｔｕｂｅꎬｓｔｅｅｌｃｏｎｔｅｎｔａｎｄｓｔｅｅｌｔｕｂｅｓｔｒｅｎｇｔｈ.Ｔｈｒｏｕｇｈｏｒｔｈｏｇｏｎａｌｔｅｓｔｔｈｅｓｅｎｓｉｔｉｖｉｔｙｏｆｔｈｅｓｅｄｉｆｆｅｒｅｎｔｆａｃｔｏｒｓｏｎｆｉｒｅｒｅｓｉｓｔａｎｃｅｌｉｍｉｔｗａｓａｎａｌｙｚｅｄꎬａｎｄｆｉｎａｌｌｙａｓｉｍｐｌｉｆｉｅｄｆｏｒｍｕｌａｆｏｒｃａｌｃｕｌａｔｉｎｇｔｈｅｆｉｒｅｒｅｓｉｓｔａｎｃｅｌｉｍｉｔｏｆｔｈｅｓｐｅｃｉｍｅｎｗａｓｐｒｏｐｏｓｅｄ.Ｔｈｅｆｉｒｅｒｅｓｉｓｔａｎｃｅｌｉｍｉｔｏｆｔｈｅｓｐｅｃｉｍｅｎｗａｓｎｅｇａｔｉｖｅｌｙｃｏｒｒｅｌａｔｅｄｗｉｔｈｔｈｅｉｎｃｒｅａｓｅｏｆｆｉｒｅｌｏａｄｒａｔｉｏａｎｄｓｉｇｎｉｆｉｃａｎｔｌｙｒｅｄｕｃｅｄꎬｏｔｈｅｒｉｎｆｌｕｅｎｃｉｎｇｆａｃｔｏｒｓｗｅｒｅｐｏｓｉｔｉｖｅｌｙｃｏｒｒｅｌａｔｅｄꎬａｎｄｓｔｅｅｌｐｉｐｅｓｔｒｅｎｇｔｈｈａｄｔｈｅｌｏｗｅｓｔｄｅｇｒｅｅｏｆｉｎｆｌｕｅｎｃｅｏｎｆｉｒｅｒｅｓｉｓｔａｎｃｅｌｉｍｉｔꎻｔｈｅｏｒｅｔｉｃａｌｃａｌｃｕｌａｔｉｏｎｒｅｓｕｌｔｓｏｆｔｈｅｆｉｒｅｒｅｓｉｓｔａｎｃｅｌｉｍｉｔａｎｄｔｈｅｆｉｎｉｔｅｅｌｅｍｅｎｔｒｅｓｕｌｔｓｗｅｒｅｉｎｇｏｏｄａｇｒｅｅｍｅｎｔ.Ｔｈｅｒｅｓｔｒａｉｎｉｎｇｅｆｆｅｃｔｏｆｔｈｅｓｔｅｅｌｐｉｐｅｈａｓａｃｅｒｔａｉｎｉｎｆｌｕｅｎｃｅｏｎｆｉｒｅｒｅｓｉｓｔａｎｃｅｌｉｍｉｔｏｆｔｈｅｓｐｅｃｉｍｅｎꎬａｎｄｒｅｓｔｒａｉｎｔｅｆｆｅｃｔｆａｃｔｏｒｉｓｇｒｅａｔｅｒｔｈａｎ１１２ｉｎｔｈｅｅｎｇｉｎｅｅｒｉｎｇｄｅｓｉｇｎａｓｆａｒａｓｐｏｓｓｉｂｌｅꎻｔｈｅｌｏａｄｒａｔｉｏｏｆ０４ｉｓｓｅｌｅｃｔｅｄꎬｔｈｅｃｏｎｃｒｅｔｅｓｔｒｅｎｇｔｈｏｆｔｈｅｓｔｅｅｌｐｉｐｅｉｓ６０ＭＰａꎬｔｈｅｓｔｅｅｌｃｏｎｔｅｎｔｉｓ００６７９ꎬａｎｄｓｔｅｅｌｐｉｐｅｓｔｒｅｎｇｔｈｉｓ３９０ＭＰａｃｏｍｂｉｎｅｄｗｉｔｈｂｅｓｔｆｉｒｅｒｅｓｉｓｔａｎｃｅｐｅｒｆｏｒｍａｎｃｅ.Ｋｅｙｗｏｒｄｓ:ｌａｔｔｉｃｅｃｏｎｃｒｅｔｅｆｉｌｌｅｄｓｔｅｅｌｔｕｂｅꎻｓｈａｐｅｄｃｏｌｕｍｎꎻｆｉｒｅꎻｆｉｎｉｔｅｅｌｅｍｅｎｔａｎａｌｙｓｉｓꎻｆｉｒｅｒｅｓｉｓｔａｎｃｅｌｉｍｉｔ㊀㊀近年来ꎬ格构式钢管混凝土柱广泛应用于风电工程㊁大跨桥梁及高层建筑中[１－３]ꎮ在发生火灾事故时ꎬ由于直接暴露于外部环境ꎬ钢管表面快速升温ꎬ材料强度快速退化ꎬ进尔导致结构破坏ꎮ在钢管表面涂抹防火涂料能较好解决这一问题ꎬ但因其造价高和施工繁琐等问题限制了这一措施在实际工程中的广泛应用[４－６]ꎮ钢管混凝土叠合柱应运而生ꎬ钢管外部混凝土具有热惰性和低热传导率ꎬ有效延缓了钢管混凝土快速升温ꎬ保证钢管混凝土有效发挥作用ꎮ学者们对钢管混凝土叠合柱已有的较深入的研究中ꎬ截面形式多集中在方形和圆形[７－１１]ꎬ人们生活需求逐渐提高ꎬ对建筑功能的要求逐日增加ꎬ常规设计形式不能满足用户对室内美观度㊁房屋有效使用面积的需求ꎮ综上所述ꎬ笔者提出了内置格构式圆钢管混凝土(Ｌ￣ＣＦＲＳＴ)十字形短柱ꎬ较好地解决室内柱脚突出问题ꎮ钢管之间通过缀板连接ꎬ缀板与钢管外部钢筋骨架降低了粘结滑移ꎬ保证混凝土与钢材共同工作[１３]ꎮ鉴于此ꎬ笔者基于ＡＢＡＱＵＳ有限元软件ꎬ建立温度场和耐火极限有限元分析模型ꎬ考虑十字形柱每个阴角所在房间同时发生火灾ꎬ进行四处阴角受火温度场试验ꎻ研究火灾荷载比㊁截面含钢率㊁钢管强度和钢管内混凝土强度等参数对耐火极限的影响ꎬ并根据正交试验分析确定最优耐火极限组合ꎻ结合参数分析和正交试验结果ꎬ考虑火灾荷载比㊁钢管内混凝土强度和含钢率等因素提出了内置格构式圆钢管混凝土十字形短柱四处阴角受火下轴压耐火极限简化计算公式ꎬ可为相关工程应用提供理论支撑１㊀有限元模型ＡＢＡＱＵＳ有限元软件提供两种热力耦合分析方法ꎬ一种为顺序热力耦合 ꎬ另一种为完全热力耦合 ꎮ前者进行耐火极限计算时试件内部温度场对力场影响较大ꎻ后者同时考虑试件温度场和力场的相互作用ꎬ计算时不易收敛ꎬ因此ꎬ采用前者进行内置格构式圆钢管混凝土十字形短柱耐火性能分析ꎮ建立如图１所示的内置格构式圆钢管混凝土十字形短柱受火有限元分析模型ꎮ图１㊀试件受火模型Ｆｉｇ１㊀Ｆｉｒｅｍｏｄｅｌｏｆｔｈｅｓｐｅｃｉｍｅｎ２３６㊀沈阳建筑大学学报(自然科学版)第３９卷㊀㊀温度场计算模型中ꎬ混凝土采用ＤＣ３Ｄ８三维传热实体单元ꎬ钢管和端板采用ＤＳ４二维传热壳单元ꎬ钢筋采用ＤＣ１Ｄ２二维传热线单元ꎮ热分析类别设置为瞬态传热ꎮ考虑实际环境温度ꎬ设置预定义场初始温度为１０ħꎮ考虑实际水分蒸发ꎬ有限元内调整在１００ħ时混凝土的比热ꎬ采用修正后的钢材和混凝土参数模型[１４]ꎮ对流传热系数取２５Ｗ/(ｍ２Ｋ)ꎬ综合辐射系数取０５ꎬ非受火面按绝热面处理[１５]ꎮ假定完全传热ꎬ采用绑定约束(Ｔｉｅ)二者之间相互作用ꎮ钢筋与混凝土的传热视为嵌入(Ｅｍｂｅｄｅｄ)混凝土中ꎮ力场计算模型中ꎬ端板假设为刚性板ꎬ杨氏模量取２０ˑ１０１５ＭＰａꎬ模型网格划分与温度场计算模型保持一致ꎬ保证温度节点读入准确ꎮ通过网格敏感性分析ꎬ保证计算效率和精度ꎬ划分计算模型网格长为２０ｍｍꎮ对于钢混组合构件高温下本构关系ꎬＴＴＬｉｅ[１６]和韩林海[１７]提出的高温下混凝土和钢材的本构模型计算结果均取有较好的精确度ꎬ钢材本构关系选用文献[１６]提出的高温下应力￣应变模型ꎬ混凝土的本构关系选用文献[１７]提出的高温下应力￣应变模型ꎮ混凝土采用ＡＢＡＱＵＳ提供的塑性损伤模型ꎬ热膨胀系数α＝(０００８Ｔ/６)ˑ１０－６ꎮ混凝土采用Ｃ３Ｄ８Ｒ八节点三维实体单元ꎬ钢管采用Ｓ４Ｒ四节点壳单元ꎬ钢筋采用Ｔ３Ｄ２二节点线单元ꎮ定义钢管内外表面与混凝土接触作用(ｓｕｒｆａｃｅｔｏｓｕｒｆａｃｅ):法向为硬接触ꎬ假定完全传力ꎻ切向为库伦摩擦ꎬ摩擦系数取０２５[１４]ꎬ钢筋采用内置区域(Ｅｍｂｅｄ)ꎬ设置为相互作用ꎮ柱下部设置为固定端ꎬ柱上部限制ｘ㊁ｙ方向平动和转动位移ꎬ向ｚ轴负方向施加轴向荷载ꎮ２㊀算例验证２１㊀火灾试验内置格构式钢管混凝土十字形短柱四处阴角受火示意图和试件内部热电偶布置如图２(ａ)㊁(ｂ)所示ꎮ在试件中部截面埋置热电偶ꎬ字母ｓ表示钢材测温点ꎬ字母ｃ表示混凝土测温点ꎮ非受火面处理如图２(ｃ)所示ꎮ在柱身凸面均匀涂抹高温耐火胶泥ꎬ确保岩棉与柱身完全粘贴ꎮ岩棉粘贴厚度为５０ｍｍꎬ导热系数为００４１Ｗ/(ｍＫ)ꎬ二者复合使整个非受火面具有很好的阻断隔热作用ꎬ可以达到模拟凸面非受火边界条件目的ꎮ试件几何参数:试件受火高度９８０ｍｍꎻ截面宽度４６０ｍｍꎬ肢宽１８０ｍｍꎬ肢厚１４０ｍｍꎻ纵筋直径１０ｍｍꎬ柱内均匀布置４根ꎻ钢管壁厚５ｍｍꎬ外径１０２ｍｍꎻ受火区箍筋直径８ｍｍꎬ间距１５０ｍｍꎮ两端设置加载头ꎬ防止轴压时混凝土局部破坏ꎮ试件截面尺寸及配筋如图３所示ꎮ图２㊀温度场试验Ｆｉｇ２㊀Ｔｅｍｐｅｒａｔｕｒｅｆｉｅｌｄｔｅｓｔ第２期陈海彬等:内置Ｌ￣ＣＦＲＳＴ十字形短柱耐火性能有限元分析２３７㊀图３㊀试件截面尺寸及配筋图Ｆｉｇ３㊀Ｓｅｃｔｉｏｎｓｉｚｅａｎｄｒｅｉｎｆｏｒｃｅｍｅｎｔｏｆｓｐｅｃｉｍｅｎ２２㊀温度场验证与试验结果分析图４为有限元模拟值与试验实测值曲线对比图ꎬ图５为升温１２０ｍｉｎ时试件中段内部混凝土温度梯度ꎮ由图可知:热工参数模型能较好反映时间内部温度变化趋势ꎬ温度场模型可靠ꎻ温度场模拟值相较于试验值略高ꎬ混凝土在１００ħ时有明显的屈服平台ꎬ主要原因是混凝土内部自由水和结晶水的蒸发ꎻ在升温１２０ｍｉｎ后ꎬ钢管内混凝土ｃ１测点温度约为１２０ħꎬ而环境温度已达到１０５０ħꎬ内外温差接近９倍ꎮ阴角处ｓ４㊁ｓ５测点距试件外表面深度相同ꎬ但最高温度差别较大ꎬ相差约４７７％ꎬ这是因为ｓ４处于凸面处直接吸收外部热量ꎬ而ｓ５处于凹面处热量能被相邻凸面吸收ꎻ可以看出越靠近十字形中心ꎬ温度变化速率越小ꎬ温度由表面向中心递减ꎬ钢管内混凝土由于钢管外混凝土阻热作用温度变化更小ꎬ保证内置格构式钢管混凝土能较好地抵抗竖向荷载ꎬ提高构件耐火性能ꎮ图４㊀温度曲线对比图Ｆｉｇ４㊀Ｔｅｍｐｅｒａｔｕｒｅｐｒｏｆｉｌｅｃｏｍｐａｒｉｓｏｎｃｈａｒｔ图５㊀柱中截面温度梯度图Ｆｉｇ５㊀Ｔｅｍｐｅｒａｔｕｒｅｇｒａｄｉｅｎｔｄｉａｇｒａｍｏｆｔｈｅｃｒｏｓｓ￣ｓｅｃｔｉｏｎｉｎｔｈｅｃｏｌｕｍｎ㊀㊀温度模拟曲线与试验实测温度曲线存在一定误差ꎮ主要原因是一方面由于钢管内㊁外混凝土养护与成型过程中收缩与钢管产生一定空隙ꎬ导致实际热量向内传导出现损失ꎻ另一方面有限元模型假定钢管与混凝土完全传热ꎬ没有考虑接触热阻ꎬ最终实测曲线与模拟曲线出现一定误差ꎬ但整体吻合程度良好ꎮ２３㊀耐火极限模型验证由于缺乏对内置格构式圆钢管混凝土十字形短柱耐火极限试验研究ꎬ根据试件内部构造组成:钢管外混凝土￣钢管￣钢管内混凝土ꎬ可按构造归类视为普通钢管混凝土叠合异形柱(劲性钢管混凝土异形柱)ꎬ同时进行普通钢管混凝土柱进行验证ꎮ选取文献[１７]中２１个试件ꎬ验证高温下本构关系㊁单元类型及建模方法的准确性ꎮ图６(ａ)㊁(ｂ)给出部分验证试件位移￣时间曲线ꎬ可以看出曲线较好地反应试验中构件变形趋势ꎬ图６(ｃ)为验证试件耐火极限计算值与试验值比２３８㊀沈阳建筑大学学报(自然科学版)第３９卷值的散点图ꎬ计算值与试验值比值的平均值μ＝０９６７ꎬ均方差σ＝０１９０９７ꎬ比值点基本落在４５ʎ斜线上ꎬ少部分点发生偏离ꎮ有限元计算结果与试验结果吻合较好ꎮ图６㊀计算值与试验值对比验证Ｆｉｇ６㊀Ｃｏｍｐａｒｉｓｏｎｂｅｔｗｅｅｎｓｉｍｕｌａｔｉｏｎｒｅｓｕｌｔｓａｎｄｔｅｓｔｒｅｓｕｌｔｓ３㊀参数分析为进一步探究试件耐火性能ꎬ用正交试验法共设计８１种工况下的内置格构式圆钢管混凝土十字形短柱耐火极限有限元模型ꎬ即改变火灾荷载比ｎ㊁试件含钢率α㊁钢管屈服强度ｆｙ和钢管内混凝土立方体强度ｆｃｕ１中任何影响因素时所有试件总量ꎮ表１列出部分试件参数ꎮ表１㊀部分试件参数Ｔａｂｌｅ１㊀Ｐａｒｔｉａｌｓｐｅｃｉｍｅｎｐａｒａｍｅｔｅｒｓ试件编号ａˑｂˑｃ/ｍｍＬ/ｍｍｎｔｓ/ｍｍｆｙ/ＭＰａｆｃｕ１/ＭＰａｆｃｕ２/ＭＰａρｓ/％Ｘ￣５￣５￣２３５￣６０４６０ˑ１８０ˑ１６０１４２００.５５２３５６０３００.７１Ｘ￣５￣６￣２３５￣６０４６０ˑ１８０ˑ１６０１４２００.６５２３５６０３００.７１Ｘ￣４￣４￣２３５￣６０４６０ˑ１８０ˑ１６０１４２００.４４２３５６０３００.７１Ｘ￣６￣４￣２３５￣６０４６０ˑ１８０ˑ１６０１４２００.４６２３５６０３００.７１Ｘ￣５￣４￣３４５￣６０４６０ˑ１８０ˑ１６０１４２００.４５３４５６０３００.７１Ｘ￣５￣４￣３９０￣６０４６０ˑ１８０ˑ１６０１４２００.４５３９０６０３００.７１Ｘ￣５￣４￣２３５￣４０４６０ˑ１８０ˑ１６０１４２００.４５２３５４０３００.７１Ｘ￣５￣４￣２３５￣５０４６０ˑ１８０ˑ１６０１４２００.４５２３５５０３００.７１Ｘ￣５￣４￣２３５￣６０４６０ˑ１８０ˑ１６０１４２００.４５２３５６０３００.７１㊀㊀注:以试件编号Ｘ￣５￣４￣２３５￣６０为例ꎬ字母Ｘ代表十字形截面ꎬ数字５㊁４㊁２３５㊁６０分别代表钢管壁厚㊁火灾荷载比㊁钢管强度㊁钢管内混凝土强度ꎻａ㊁ｂ㊁ｃ分别为截面宽度㊁肢宽和肢厚ꎻＬ为试件总高度ꎻ火灾荷载比ｎ(ｎ＝Ｎｆ/Ｎｕ)为构件火灾下承受荷载Ｎｆ与常温下极限承载力Ｎｕ比值ꎻ含钢率α变化表现在钢管壁厚ｔｓ上ꎬ即４ｍｍ㊁５ｍｍ和６ｍｍꎻρｓ为截面纵筋配筋率ꎻｆｃｕ２为钢管外混凝土立方体抗压强度ꎮ３１㊀火灾荷载比图７为３种含钢率下火灾荷载比￣耐火极限变化规律图ꎬ由图７可知:所有试件耐火极限均随火灾荷载比的增大而显著降低ꎻ火灾荷载比由０４增至０６过程中ꎬ以内部构造α＝００４６２ꎬｆｙ＝３９０ＭＰａꎬｆｃｕ１＝５０ＭＰａ的试件耐火极限降低最少ꎬ为５０６３％ꎬ以内部构造为α＝００４６２ꎬｆｙ＝２３５ＭＰａꎬｆｃｕ１＝６０ＭＰａ的试件耐火极限降低最多ꎬ为６０９％ꎻ即使在火灾荷载比０６下ꎬ大部分试件均满足一级耐火等级的需求ꎬ表现出良好的耐火性能ꎮ火灾荷载比的增加使受火时试件承受更大的荷载ꎬ同时试件受高温的不利影响ꎬ使试件更快达到耐火极限ꎮ第２期陈海彬等:内置Ｌ￣ＣＦＲＳＴ十字形短柱耐火性能有限元分析２３９㊀图７㊀火灾荷载比对耐火极限的影响Ｆｉｇ７㊀Ｅｆｆｅｃｔｓｏｆｌｏａｄｒａｔｉｏｏｎｆｉｒｅｒｅｓｉｓｔａｎｃｅｌｉｍｉｔ３２㊀钢管内混凝土强度图８给出３种火灾荷载比下钢管内混凝土强度￣耐火极限变化规律ꎬ由图８可知:钢管内混凝土强度与耐火极限呈正相关ꎬ在相同火灾荷载比下ꎬ以试件Ｘ￣５￣４￣２３５￣４０为例ꎬ钢管内混凝土强度由４０ＭＰａ提升至５０ＭＰａ时ꎬ试件耐火极限增加１６５３％ꎬ由５０ＭＰａ提升至６０ＭＰａ时ꎬ耐火极限提高１７３％ꎬ混凝土强度的提高对构件耐火极限提升影响较明显ꎻ当钢管强度为２３５ＭＰａ㊁含钢率为０４６２时ꎬ混凝土强度由４０ＭＰａ提升至６０ＭＰａꎬ均出现耐火极限先增高后降低的变化趋势ꎬ这是由于钢管约束效应系数ξ值减小ꎬ钢管对混凝土的约束作用减弱ꎬ而钢管内混凝土本构关系与ξ值的大小有关ꎬ已有研究表明ξ值越大ꎬ钢管对混凝土约束作用越强ꎬ混凝土应力￣应变曲线呈单调递增趋势ꎮ实际工程应用中建议保持ξ值大于１１２ꎮ图８㊀钢管内混凝土强度对耐火极限的影响Ｆｉｇ８㊀Ｅｆｆｅｃｔｏｆｃｏｎｃｒｅｔｅｉｎｔｈｅｓｔｅｅｌｔｕｂｅｏｎｆｉｒｅｒｅｓｉｓｔａｎｃｅｌｉｍｉｔ３３㊀含钢率图９为３种火灾荷载比下含钢率￣耐火极限变化规律图ꎮ由图９可知:含钢率与耐火极限呈正相关ꎬ在相同荷载下ꎬ以试件Ｘ￣４￣４￣２３５￣６０为例ꎬ试件含钢率从００４６２增至００５７２时ꎬ耐火极限增加３２０３％ꎬ含钢率从００５７２增至００６７９时ꎬ耐火极限增加１００５％ꎬ含钢率提高后ꎬ钢管对钢管内混凝土约束效应增强ꎬ管内混凝土性能得到更好发挥ꎻ钢管内混凝土强度为６０ＭＰａ㊁钢管强度为２３５时ꎬ可以看出ꎬ在各个火灾荷载比下含钢率由００４６２提升至００６７９时ꎬ耐火极限增长变化量快速提高ꎬ与钢管混凝土强度提升变化趋势类似ꎬ钢管约束效应系数增大ꎬ钢管约束效应明显ꎬ试件整体承载力提高ꎬ耐火极限提高ꎮ２４０㊀沈阳建筑大学学报(自然科学版)第３９卷图９㊀含钢率对耐火极限的影响Ｆｉｇ９㊀Ｅｆｆｅｃｔｏｆｓｔｅｅｌｃｏｎｔｅｎｔｏｎｆｉｒｅｒｅｓｉｓｔａｎｃｅ３４㊀钢管强度图１０给出在３种火灾荷载比下钢管强度￣耐火极限变化规律ꎮ由图１０可知ꎬ钢管强度与耐火极限呈正相关ꎬ关系近似为线性增长ꎮ相同荷载下ꎬ以试件Ｘ￣５￣４￣２３５￣６０为例ꎬ钢管强度由２３５ＭＰａ增至３４５ＭＰａ时ꎬ耐火极限增加１８６４％ꎬ钢管强度由３４５ＭＰａ增至３９０ＭＰａ时ꎬ耐火极限仅增加６４％ꎬ由此可见提升钢管强度对增加耐火极限效果并不明显ꎮ图１０㊀钢管强度对耐火极限的影响Ｆｉｇ１０㊀Ｅｆｆｅｃｔｏｆｓｔｅｅｌｐｉｐｅｓｔｒｅｎｇｔｈｏｎｆｉｒｅｒｅｓｉｓｔａｎｃｅ４㊀抗火设计组合建议利用正交表Ｌ９(３４)分析４种因素对耐火极限的影响ꎬ正交试验表如表２所示ꎬ各因素水平平均值和极差如表３所示ꎮ表３中ꎬＫｉ表示在因素火灾荷载比下的耐火极限之和ꎻ Ｋｉ(ｉ＝１ꎬ２ꎬ３)为Ｋｉ平均值ꎻ极差Ｒ的大小反应四个因素的重要性ꎮ由预期参数分析和Ｒ值大小可知ꎬ影响程度从大到小依次为火灾荷载比㊁钢管内混凝土强度㊁含钢率㊁钢管强度ꎮ内置格构式圆钢管混凝土十字形短柱耐火极限的最佳组合为表２㊀耐火极限正交分析Ｔａｂｌｅ２㊀Ｏｒｔｈｏｇｏｎａｌａｎａｌｙｓｉｓｏｆｆｉｒｅｒｅｓｉｓｔａｎｃｅｌｉｍｉｔ试验编号ｎαｆｙ/ＭＰａｆｃｕ/ＭＰａ时间/ｍｉｎ１０.４０.０４６２２３５４０２１９２０.４０.０５７２３４５５０３５１３０.４０.０６７９３９０６０４７５４０.５０.０４６２３４５６０２２７５０.５０.０５７２３９０４０２１５６０.５０.０６７９２３５５０２０８７０.６０.０４６２３９０５０１５６８０.６０.０５７２２３５６０２５４９０.６０.０６７９３４５４０１６４第２期陈海彬等:内置Ｌ￣ＣＦＲＳＴ十字形短柱耐火性能有限元分析２４１㊀表３㊀各因素水平㊁平均值和极差Ｔａｂｌｅ３㊀Ａｖｅｒａｇｅｖａｌｕｅａｎｄｅｘｔｒｅｍｅｌｙｐｏｏｒｌｅｖｅｌｓｏｆａｌｌｆａｃｔｏｒｓ指标ｎαｆｙ/ＭＰａｆｃｕ/ＭＰａＫ１１０４５６０２６８１５９８Ｋ２６５０８２０７４２７１５Ｋ３５７４８４７８４６９５６Ｋ１３４８.３２００.７２２７.０１９９.３Ｋ２２１６.７２７３.３２４７.３２３８.３Ｋ３１９１.３２８２.３２８２.０３１８.７极差Ｒ１５７.０８１.６５５.０１１９.４火灾荷载比为０４㊁含钢率为００６７９㊁钢管强度为３９０ＭＰａ㊁钢管内混凝土强度为６０ＭＰａꎬ这种组合耐火性能最好ꎮ结合上述分析ꎬ提升钢管强度不满足经济性和适用性原则ꎮ５㊀耐火极限简化计算国内外对于内置格构式圆钢管混凝土十字形短柱阴角受火下的耐火极限计算公式较为匮乏ꎬ结合参数分析和正交分析结果ꎬ选取实际工程中适用性较广的３类因素ꎬ即火灾荷载比０４~０６㊁钢管内混凝土强度４０~６０ＭＰａ和含钢率００４６２~００６７９ꎮ鉴于短柱不发生失稳破坏ꎬ暂不考虑长细比的影响ꎬ综合有限元数值模拟结果ꎬ采用幂函数的函数方程对内置格构式圆钢管混凝土十字形短柱耐火极限进行多元非线性回归ꎮ得出耐火极限计算简化计算公式:ｔ＝１.５０３ˑｎ－１.９１３ｆ０.６２６ｃｕ(１００α)０.６９９.(１)得到上述理论计算公式与数值模拟结果比值ꎬＲ２＝０９９８ꎬ能较好计算构件耐火极限ꎮ６㊀结㊀论(１)火灾荷载比和钢管内混凝土强度对耐火极限的影响最为明显ꎬ火灾荷载比增大会使试件耐火极限大幅下降ꎬ其他因素均呈正相关性ꎬ钢管强度的提升对于耐火极限影响不大ꎮ(２)钢管外混凝土有效延缓了钢管和钢管内混凝土升温ꎬ有效提高试件耐火性能ꎮ(３)各因素对耐火极限的敏感程度依次为火灾荷载比㊁钢管内混凝土强度㊁含钢率㊁钢管强度ꎮ当火灾荷载比为０４㊁含钢率为００６７９㊁钢管强度为３９０ＭＰａ㊁钢管内混凝土强度为６０ＭＰａ时ꎬ试件的耐火极限组合最优ꎮ(４)基于火灾荷载比㊁钢管内混凝土强度和含钢率ꎬ提出了对于四处阴角受火下耐火极限简化计算公式ꎬ为实际工程中抗火设计做参考ꎮ参考文献[１]㊀杨有福ꎬ刘敏ꎬ别雪梦.四肢格构式钢管混凝土轴压构件承载力研究[Ｊ].建筑钢结构进展ꎬ２０２２ꎬ２４(５):１８－２６.㊀(ＹＡＮＧＹｏｕｆｕꎬＬＩＵＭｉｎꎬＢＩＥＸｕｅｍｅｎｇ.Ａｒｅｓｅａｒｃｈｏｎｔｈｅｂｅａｒｉｎｇｃａｐａｃｉｔｙｏｆｆｏｕｒ￣ｌｅｇｇｅｄＣＦＳＴｌａｔｔｉｃｅｄｍｅｍｂｅｒｓｕｎｄｅｒａｘｉａｌｃｏｍｐｒｅｓｓｉｏｎ[Ｊ].Ｐｒｏｇｒｅｓｓｉｎｓｔｅｅｌｂｕｉｌｄｉｎｇｓｔｒｕｃｔｕｒｅｓꎬ２０２２ꎬ２４(５):１８－２６.) [２]㊀高春彦ꎬ赵洁ꎬ程亚超.格构式钢管混凝土风电塔架新型附着式节点受力性能研究[Ｊ].应用力学学报ꎬ２０２０ꎬ３７(６):２４４０－２４４５.㊀(ＧＡＯＣｈｕｎｙａｎꎬＺＨＡＯＪｉｅꎬＣＨＥＮＧＹａｃｈａｏ.Ｍｅｃｈａｎｉｃａｌｂｅｈａｖｉｏｒｓｔｕｄｙｏｎｔｈｅａｔｔａｃｈｍｅｎｔｔｙｐｅｃｏｎｃｒｅｔｅ￣ｆｉｌｌｅｄｓｔｅｅｌｔｕｂｕｌａｒｌａｔｔｉｃｅｗｉｎｄｔｏｗｅｒ[Ｊ].Ｃｈｉｎｅｓｅｊｏｕｒｎａｌｏｆａｐｐｌｉｅｄｍｅｃｈａｎｉｃｓꎬ２０２０ꎬ３７(６):２４４０－２４４５.) [３]㊀史益.格构式桥墩在山区公路桥梁加固中的应用[Ｊ].中国公路ꎬ２０２０(８):１００－１０１.㊀(ＳＨＩＹｉ.Ａｐｐｌｉｃａｔｉｏｎｏｆｌａｔｔｉｃｅｐｉｅｒｉｎｓｔｒｅｎｇｔｈｅｎｉｎｇｈｉｇｈｗａｙｂｒｉｄｇｅｓｉｎｍｏｕｎｔａｉｎｏｕｓａｒｅａｓ[Ｊ].Ｃｈｉｎａｈｉｇｈｗａｙꎬ２０２０(８):１００－１０１.) [４]㊀尹亮ꎬ倪照鹏ꎬ叶继红ꎬ等.厚型涂料保护的钢管混凝土巨型柱防火性能研究[Ｊ].建筑结构学报ꎬ２０１５ꎬ３６(增刊１):３０５－３０９.㊀(ＹＩＮＬｉａｎｇꎬＮＩＺｈａｏｐｅｎｇꎬＹＥＪｉｈｏｎｇꎬｅｔａｌ.ＳｔｕｄｙｏｎｆｉｒｅｐｒｏｔｅｃｔｉｏｎｐｅｒｆｏｒｍａｎｃｅｏｆＣＦＳＴｍｅｇａ￣ｃｏｌｕｍｎｓｐｒｏｔｅｃｔｅｄｂｙｔｈｉｃｋｃｏａｔｅｄｆｉｒｅｒｅｔａｒｄａｎｔｃｏａｔｉｎ[Ｊ].Ｊｏｕｒｎａｌｏｆｂｕｉｌｄｉｎｇｓｔｒｕｃｔｕｒｅｓꎬ２０１５ꎬ３６(Ｓ１):３０５－３０９.) [５]㊀赵炳震ꎬ陈志华ꎬ郑培壮ꎬ等.ＡＬＣ板防护下的方钢管混凝土组合异形柱耐火试验[Ｊ].天津大学学报(自然科学与工程技术版)ꎬ２０１７ꎬ５０(９):９３１－９３８.㊀(ＺＨＡＯＢｉｎｇｚｈｅｎꎬＣＨＥＮＺｈｉｈｕａꎬＺＨＥＮＧＰｅｉｚｈｕａｎｇꎬｅｔａｌ.ＦｉｒｅｒｅｓｉｓｔａｎｃｅｅｘｐｅｒｉｍｅｎｔｏｎＳＣＦＲＴｃｏｌｕｍｎｉｎｓｕｌａｔｅｄｗｉｔｈＡＬＣｂｏａｒｄ[Ｊ].ＪｏｕｒｎａｌｏｆＴｉａｎｊｉｎｕｎｉｖｅｒｓｉｔｙ(ｓｃｉｅｎｃｅａｎｄｔｅｃｈｎｏｌｏｇｙ)ꎬ２０１７ꎬ５０(９):９３１－９３８.) [６]㊀周威ꎬ毕颖ꎬ赵磊.防火涂料局部脱落的钢管２４２㊀沈阳建筑大学学报(自然科学版)第３９卷混凝土柱温度场有限元分析[Ｊ].消防科学与技术ꎬ２０２２ꎬ４１(１):４１－４７.㊀(ＺＨＯＵＷｅｉꎬＢＩＹｉｎｇꎬＺＨＡＯＬｅｉ.ＦｉｎｉｔｅｅｌｅｍｅｎｔａｎａｌｙｓｉｓｏｎｔｈｅｔｅｍｐｅｒａｔｕｒｅｄｉｓｔｒｉｂｕｔｉｏｎｏｆＣＦＳＴｃｏｌｕｍｎｓｗｉｔｈｌｏｃａｌｄａｍａｇｅｏｆｆｉｒｅｐｒｏｔｅｃｔｉｏｎ[Ｊ].Ｆｉｒｅｓｃｉｅｎｃｅａｎｄｔｅｃｈｎｏｌｏｇｙꎬ２０２２ꎬ４１(１):４１－４７.)[７]㊀王振山ꎬ雷震ꎬ李浩炜ꎬ等.螺旋加劲薄壁方钢管混凝土叠合构件轴压性能及参数影响研究[Ｊ].建筑科学ꎬ２０２２ꎬ３８(１):２５－３２.㊀(ＷＡＮＧＺｈｅｎｓｈａｎꎬＬＥＩＺｈｅｎꎬＬＩＨａｏｗｅｉꎬｅｔａｌ.Ｒｅｓｅａｒｃｈｏｎｎｏｎｌｉｎｅａｒｂｅｈａｖｉｏｒｏｆｃｏｎｃｒｅｔｅｆｉｌｌｅｄｔｈｉｎ￣ｗａｌｌｅｄｓｑｕａｒｅｓｔｅｅｌｔｕｂｕｌａｒｃｏｍｐｏｓｉｔｅｍｅｍｂｅｒｓｗｉｔｈｓｐｉｒａｌｓｔｉｆｆｅｎｅｒｓｕｎｄｅｒａｘｉａｌｃｏｍｐｒｅｓｓｉｏｎ[Ｊ].Ｂｕｉｌｄｉｎｇｓｃｉｅｎｃｅꎬ２０２２ꎬ３８(１):２５－３２.)[８]㊀王振山ꎬ李亚坤ꎬ韦俊ꎬ等.螺旋肋薄壁钢管混凝土叠合柱滞回性能数值分析研究[Ｊ].应用力学学报ꎬ２０２１ꎬ３８(６):２２９８－２３０５.㊀(ＷＡＮＧＺｈｅｎｓｈａｎꎬＬＩＹａｋｕｎꎬＷＥＩＪｕｎꎬｅｔａｌ.Ｈｙｓｔｅｒｅｔｉｃｂｅｈａｖｉｏｒａｎｄｎｕｍｅｒｉｃａｌａｎａｌｙｓｉｓｏｆｔｈｉｎ￣ｗａｌｌｅｄｃｏｎｃｒｅｔｅ￣ｅｎｃａｐｓｕｌａｔｅｄｓｔｅｅｌｔｕｂｕｌａｒｃｏｍｐｏｓｉｔｅｃｏｌｕｍｎｗｉｔｈｓｐｉｒａｌｒｉｂｓ[Ｊ].Ｃｈｉｎｅｓｅｊｏｕｒｎａｌｏｆａｐｐｌｉｅｄｍｅｃｈａｎｉｃｓꎬ２０２１ꎬ３８(６):２２９８－２３０５.)[９]㊀牛海成ꎬ高锦龙ꎬ吉珈琨ꎬ等.钢管高强再生混凝土叠合柱轴压性能[Ｊ].复合材料学报ꎬ２０２２ꎬ３９(８):３９９４－４００４.㊀(ＮＩＵＨａｉｃｈｅｎｇꎬＧＡＯＪｉｎｌｏｎｇꎬＪＩＪｉａｋｕｎꎬｅｔａｌ.Ａｘｉａｌｃｏｍｐｒｅｓｓｉｏｎｂｅｈａｖｉｏｒｏｆｈｉｇｈ￣ｓｔｒｅｎｇｔｈｒｅｃｙｃｌｅｄｃｏｎｃｒｅｔｅｆｉｌｌｅｄｓｔｅｅｌｔｕｂｕｌａｒｃｏｍｐｏｓｉｔｅｃｏｌｕｍｎｓ[Ｊ].Ａｃｔａｍａｔｅｒｉａｅｃｏｍｐｏｓｉｔａｅｓｉｎｉｃａꎬ２０２２ꎬ３９(８):３９９４－４００４.)[１０]赵晖ꎬ张颖ꎬ王蕊.中空方形钢管混凝土叠合柱轴压力学性能研究[Ｊ].建筑结构学报ꎬ２０２２ꎬ４３(６):５３－６２.㊀(ＺＨＡＯＨｕｉꎬＺＨＡＮＧＹｉｎｇꎬＷＡＮＧＲｕｉ.Ｓｔｕｄｙｏｎｍｅｃｈａｎｉｃａｌｂｅｈａｖｉｏｒｏｆｓｑｕａｒｅｈｏｌｌｏｗｃｏｎｃｒｅｔｅ￣ｅｎｃａｓｅｄＣＦＳＴｃｏｌｕｍｎｓｗｉｔｈｉｎｎｅｒｓｔｅｅｌｐｌａｔｅｕｎｄｅｒａｘｉａｌｃｏｍｐｒｅｓｓｉｏｎ[Ｊ].Ｊｏｕｒｎａｌｏｆｂｕｉｌｄｉｎｇｓｔｒｕｃｔｕｒｅｓꎬ２０２２ꎬ４３(６):５３－６２.[１１]程志敏.圆钢管高强混凝土叠合短柱轴压力学性能研究[Ｊ].四川建筑科学研究ꎬ２０２１ꎬ４７(２):５６－６２.㊀(ＣＨＥＮＧＺｈｉｍｉｎ.Ｓｔｕｄｙｏｎｔｈｅｐｅｒｆｏｒｍａｎｃｅｏｆｃｉｒｃｕｌａｒｈｉｇｈｓｔｒｅｎｇｔｈｃｏｎｃｒｅｔｅ￣ｅｎｃａｓｅｄｃｏｎｃｒｅｔｅ￣ｆｉｌｌｅｄｓｔｅｅｌｔｕｂｅｃｏｌｕｍｎｕｎｄｅｒａｘｉａｌｃｏｍｐｒｅｓｓｉｏｎ[Ｊ].Ｓｉｃｈｕａｎｂｕｉｌｄｉｎｇｓｃｉｅｎｃｅꎬ２０２１ꎬ４７(２):５６－６２.)[１２]任庆新ꎬ魏秋宇ꎬ王鹏ꎬ等.圆中空钢管混凝土叠合长柱轴压性能研究[Ｊ].沈阳建筑大学学报(自然科学版)ꎬ２０２２ꎬ３８(３):４１０－４１７.㊀(ＲＥＮＱｉｎｇｘｉｎꎬＷＥＩＱｉｕｙｕꎬＷＡＮＧＰｅｎｇꎬｅｔａｌ.Ｒｅｓｅａｒｃｈｏｎｃｉｒｃｌｅｈｏｌｌｏｗｃｏｎｃｒｅｔｅ￣ｅｎｃａｓｅｄＣＦＳＴｓｌｅｎｄｅｒｃｏｌｕｍｎｕｎｄｅｒａｘｉａｌｃｏｍｐｒｅｓｓｉｏｎ[Ｊ].ＪｏｕｒｎａｌｏｆＳｈｅｎｙａｎｇｊｉａｎｚｈｕｕｎｉｖｅｒｓｉｔｙ(ｎａｔｕｒａｌｓｃｉｅｎｃｅ)ꎬ２０２２ꎬ３８(３):４１０－４１７.) [１３]陈海彬ꎬ周建超ꎬ王棒棒.高温后混凝土抗压强度试验研究[Ｊ].混凝土ꎬ２０２１(１０):２３－２６.㊀(ＣＨＥＮＨａｉｂｉｎꎬＺＨＯＵＪｉａｎｃｈａｏꎬＷＡＮＧＢａｎｇｂａｎｇ.Ｅｘｐｅｒｉｍｅｎｔａｌｓｔｕｄｙｏｎｃｏｍｐｒｅｓｓｉｖｅｓｔｒｅｎｇｔｈｏｆｃｏｎｃｒｅｔｅａｆｔｅｒｈｉｇｈｔｅｍｐｅｒａｔｕｒｅ[Ｊ].Ｃｏｎｃｒｅｔｅꎬ２０２１(１０):２３－２６.)[１４]宋天诣.火灾后钢￣混凝土组合框架梁￣柱节点的力学性能研究[Ｄ].北京:清华大学ꎬ２０１０.㊀(ＳＯＮＧＴｉａｎｙｉ.Ｒｅｓｅａｒｃｈｏｎｐｏｓｔ￣ｆｉｒｅｐｅｒｆｏｒｍａｎｃｅｏｆｓｔｅｅｌ￣ｃｏｎｃｒｅｔｅｃｏｍｐｏｓｉｔｅｂｅａｍ￣ｃｏｌｕｍｎｊｏｉｎｔｓ[Ｄ].Ｂｅｉｊｉｎｇ:ＴｓｉｎｇｈｕａＵｎｉｖｅｒｓｉｔｙꎬ２０１０.) [１５]刘发起.火灾下与火灾后圆钢管约束钢筋混凝土柱力学性能研究[Ｄ].哈尔滨:哈尔滨工业大学ꎬ２０１４.㊀(ＬＩＵＦａｑｉ.Ｆｉｒｅａｎｄｐｏｓｔ￣ｆｉｒｅｂｅｈａｖｉｏｕｒｓｏｆｃｉｒｃｕｌａｒｓｔｅｅｌｔｕｂｅｃｏｎｆｉｎｅｄｒｅｉｎｆｏｒｃｅｄｃｏｎｃｒｅｔｅｃｏｌｕｍｎｓ[Ｄ].Ｈａｒｂｉｎ:ＨａｒｂｉｎＩｎｓｔｉｔｕｔｅｏｆＴｅｃｈｎｏｌｏｇｙꎬ２０１４.)[１６]ＬＩＥＴＴ.Ｆｉｒｅｒｅｓｉｓｔａｎｃｅｏｆｃｉｒｃｕｌａｒｓｔｅｅｌｃｏｌｕｍｎｓｆｉｌｌｅｄｗｉｔｈｂａｒｒｅｉｎｆｏｒｃｅｄｃｏｎｃｒｅｔｅ[Ｊ].Ｊｏｕｒｎａｌｏｆｓｔｒｕｃｔｕｒａｌｅｎｇｉｎｅｅｒｉｎｇꎬ１９９４ꎬ１２０(５):１４８９－１５０９.[１７]韩林海.钢管混凝土结构￣理论与实践[Ｍ].３版.北京:科学出版社ꎬ２０１６.㊀(ＨＡＮＬｉｎｈａｉ.Ｃｏｎｃｒｅｔｅｆｉｌｌｅｄｓｔｅｅｌｔｕｂｕｌａｒｓｔｒｕｃｔｕｒｅｓ￣ｔｈｅｏｒｙａｎｄＰｒａｃｔｉｃｅ[Ｍ].３ｒｄｅｄ.Ｂｅｉｊｉｎｇ:ＳｃｉｅｎｃｅＰｒｅｓｓꎬ２０１６.)[１８]杨勇ꎬ龚志超ꎬ邓辉ꎬ等.钢管混凝土十字形截面柱耐火性能试验研究[Ｊ].建筑结构学报ꎬ２０１７ꎬ３８(１２):８８－９６.㊀(ＹＡＮＧＹｏｎｇꎬＧＯＮＧＺｈｉｃｈａｏꎬＤＥＮＧＨｕｉꎬｅｔａｌ.Ｅｘｐｅｒｉｍｅｎｔａｌｓｔｕｄｙｏｎｆｉｒｅｒｅｓｉｓｔａｎｃｅｏｆｃｒｏｓｓ￣ｓｈａｐｅｄｃｏｎｃｒｅｔｅｆｉｌｌｅｄｓｔｅｅｌｔｕｂｕｌａｒｃｏｌｕｍｎ[Ｊ].Ｊｏｕｒｎａｌｏｆｂｕｉｌｄｉｎｇｓｔｒｕｃｔｕｒｅｓꎬ２０１７ꎬ３８(１２):８８－９６.)[１９]崔志强ꎬ韩林海ꎬ宋天诣.三肢钢管混凝土格构式柱耐火性能分析[Ｊ].工程力学ꎬ２０１４ꎬ３１(增刊１):２０７－２１２.㊀(ＣＵＩＺｈｉｑｉａｎｇꎬＨＡＮＬｉｎｈａｉꎬＳＯＮＧＴｉａｎｙｉ.Ａｎａｌｙｓｉｓｏｎｆｉｒｅｐｅｒｆｏｒｍａｎｃｅｏｆｃｏｎｃｒｅｔｅ￣ｆｉｌｌｅｄｓｔｅｅｌｔｕｂｕｌａｒ(ＣＦＳＴ)ｔｒｉｍｐｌｅ￣ｌｉｍｂｌａｃｅｄｃｏｌｕｍｎｓ[Ｊ].Ｅｎｇｉｎｅｅｒｉｎｇｍｅｃｈａｎｉｃｓꎬ２０１４ꎬ３１(Ｓ１):２０７－２１２.)[２０]ＬＩＥＴＴꎬＣＨＡＢＯＴＭ.Ｅｘｐｅｒｉｍｅｎｔａｌｓｔｕｄｉｅｓｏｎｔｈｅｆｉｒｅｒｅｓｉｓｔａｎｃｅｏｆｈｏｌｌｏｗｓｔｅｅｌｃｏｌｕｍｎｓｆｉｌｌｅｄｗｉｔｈｐｌａｉｎｃｏｎｃｒｅｔｅ[Ｒ].ＮＲＣＣＮＲＣｉｎｔｅｒｎａｌｒｅｐｏｒｔꎬ１９９２.(责任编辑:王国业㊀英文审校:唐玉兰)。

ASME与EN13445分析区别

ASME与EN13445分析区别自从1914年ASME锅炉压力容器规范第一版问世以来，经过九十年的实践和不断修订，到本世纪初，欧盟颁布与压力设备指令（PED）配套EN 13445压力容器标准，犹如一声春雷，打破了世界压力容器规范的格局，形成两大权威规范并存的局面。

实际上，这是压力容器发展史上空前未有的一次大碰撞，它发出灿烂耀眼的火花。

碰撞是在压力容器的设计、材料、制造和检验多方面进行的，而主要是在设计方面，特别是在分析设计方面。

欧洲标准在披露ASME规范执行过程中遇到的棘手问题的同时，提出了他们的解决方案，在设计概念上出现了许多创新，ASME也发现其规范存在的若干不足，拨款立项，广泛征求使现行规范趋于现代化的建议。

这次大碰撞蕴育着今后压力容器设计概念的大的改革，我们必须拭目以待。

台湾著名企业家温世仁今年在北京召开的京台科技论坛上说：“从今年开始，我们要把这个论坛定位在制订两岸共同标准上，这个世界，最早的时候是生产力的竞争，后来是技术力的竞争，再过来就是所谓智慧财产权（即知识产权）的竞争。

再下来就是所谓标准之战。

未来的世界主要是标准之战。

”我国是压力容器生产大国，已能制造千吨级加氢反应器和一些核容器，已有一些压力容器出口欧美，但还不是压力容器生产强国，一些技术含量较高的压力设备还要进口。

我国压力容器标准在世界所占分额极小，我们必须在当今世界标准之战中占有一席之地。

实际上，支持标准的是包括专利在内的大量知识产权，没有知识产权的支撑，标准将苍白无力；而使标准真正起到作用，则是后续产业的强力支撑，没有后者，将无法证明标准是成功的。

据报导，截止2002年底，我国出口企业因技术壁垒引发的摩擦金额高达400多亿美元，占出口总额的30%，损失金额高达170亿美元（今年9月北京科博会2003年标准与专利北京国际论坛国家标委会有关人士透露）。

为了弄清国际贸易中的游戏规则，使我处于主动地位，我们必须认真研究当今世界压力容器标准之战中欧美两大标准体系的情况和他们对我们的影响。

复合材料SHELL181单元完全攻略

复合材料SHELL181单元完全攻略发表时间：2009-8-31 作者: 徐鹤山译蒋福庆校来源: e-works关键字: 复合材料 SHELL181 ANSYSANSYS程序中的SHELL181单元是用于复合材料层合板结构分析比较好的单元之一。

原文在ANSYS程序的在线帮助中，这篇文章是它的译文，是我们从专业角度对原文的翻译。

目的在于帮助那些英语水平不高，而且从事复合材料结构计算分析的技术人员能够方便地使用这个单元。

前言ANSYS程序中的SHELL181单元是用于复合材料层合板结构分析比较好的单元之一。

原文在ANSYS程序的在线帮助中，这篇文章是它的译文，是我们从专业角度对原文的翻译。

目的在于帮助那些英语水平不高，而且从事复合材料结构计算分析的技术人员能够方便地使用这个单元。

复合材料是由一种以上具有不同性质的材料构成的，其主要优点是具有优异的材料性能。

复合材料具有比强度大、比刚度高、抗疲劳性能好、各向异性、以及材料性能可设计的特点。

复合材料可用于飞机机翼、尾翼，发动机机匣、叶片等结构设计，也是用于压力容器、风力发电叶片等民用结构的先进材料。

目前，复合材料技术已成为影响飞机发展的关键技术之一，逐渐应用于飞机等结构的主承力构件中，西方先进战斗机上复合材料使用量已达结构总重量的25%以上。

风力发电是目前世界上能源领域发展最快的技术之一，据知大约每年以25~30%的速度递增。

当前风力发电是我国新兴的能源项目，国内有关公司和企业纷纷引进国外产品和技术，产能过剩，竞争相当激烈，但最后谁能在该行业中站住脚，还取决于有没有自己的自主知识产权的产品。

有限元技术是分析风力发电复合材料叶片的先进手段，有助于设计先进的叶片结构。

ANSYS程序中复合材料单元比较全，其中SHELL181单元是比较好的单元之一。

1. 181壳单元描述181壳单元适于分析薄至中等厚度的壳形结构。

它是每个节点具有6个自由度的4节点单元。

6个自由度指X、Y、Z三个轴方向的位移和绕X、Y、Z三个轴的转角（如选用膜片，则该单元只有位移自由度）。

Transportation Research Part C Emerging Technologies

Transient dynamic analysis of a floating beam–water interactionsystem excited by the impact of a landing beam Original ResearchArticleJournal of Sound and Vibration, Volume 303, Issues 1-2, 5 June2007, Pages 371-390J.Z. Jin, J.T. XingClose preview | Related articles | Related reference w ork articlesAbstract | Figures/Tables | ReferencesAbstractAn aircraft, idealised as an elastic beam with supporting system, lands with speed on anaircraft carrier or floating airport. The floating platform is idealised as a flexible beam floatingin an infinite water domain. The water is assumed incompressible and inviscid. The surface disturbance satisfies a linear free surface wave condition and an undisturbed condition atinfinity. A mathematical model is developed to describe this complex fluid–structureinteractive dynamical system, which exhibits strong coupling between the system'scomponents. An effective numerical scheme is established assuming that the two beam-likestructures are two solid substructures with motions represented by their respective modefunctions and the infinite fluid domain is modelled by a boundary element scheme. A mixedmode function-boundary element method is developed to solve the transient dynamics of thesystem in terms of the time histories of the beam displacement responses and waterpressure. The presented data demonstrates the applicability of the developed mathematicalmodel and numerical approach and some insights of the complex interactive processexhibited by the system.A rticle Outline1. Introduction2. Governing equations2.1. Fluid domain2.2. Landing beam2.3. Floating beam2.4. Fluid–structure interaction interface conditionPurchase$ 31.502.5. Initial conditions3. Mode equations of solid substructures3.1. Mode functions of a free –free beam3.2. Mode equation of landing beam3.3. Mode equation of floating beam4. Boundary element equation of the fluid domain5.Mixed mode function-boundary element equations6. Numerical solution7. Numerical results7.1. A simulation for a car running test7.2. An example simulating aircraft landing impacts8. ConclusionsAcknowledgements Appendix A. AppendixReferences427 Influence of modelling and solution methods on the FE-simulation of the post-buckling behaviour ofstiffened aircraft fuselage panels Original ResearchArticleComposite Structures , Volume 73, Issue 2, May 2006,Pages 229-236P. Linde, A. Schulz, W. RustClose preview | Related articles | Related reference w ork articles Abstract | Figures/Tables | ReferencesAbstractStiffened fuselage panels with laminated constructions play an increasing rolein aircraft design. The static behaviour through the buckling- and post-bucklingregime until failure has to be established. Apart from analytical calculations,experimental tests for different load combinations are indespensible, both ofwhich are expensive and time consuming.Purchase $ 31.50The virtual testing described here is based on a development project aiming at reducing the amount of experimental tests, and narrowing the numerical predictions to experimental results.A tool developed for parametric modelling and simulation of test shells is discussed.The numerical model is based on layered shell elements in ANSYS and for special purposes in LS-DYNA. It is outlined how far the behaviour of laminates (interaction of different and anisotropic materials, delamination and splices) can be simulated in this context.Results are given for welded panels and for fibre metal laminate panels. Comparison with experimental data is made. Recommendations for future research is provided.A rticle Outline1. Introduction1.1. General1.2. Objective1.3. Scope2. Model2.1. Geometry model2.2. Model for implicit analysis2.3. Model for explicit analysis2.4. FE-model for LS-DYNA2.5. Splices2.6. Delaminations2.7. Boundary conditions3. Computation 3.1. General 3.2. Static solution3.3. Implicit dynamic solution3.4. Explicit dynamic solution4. Results5. Summary, conclusions5.1.Summary5.2. Conclusions5.3. RecommendationsAcknowledgementsReferences428 Extratropical case study of stratosphere –troposphere exchange using multivariate analyses from mozaicaircraft data Original Research ArticleAtmospheric Environment , Volume 39, Issue 35,November 2005, Pages 6537-6549François Borchi, Emmanouil Oikonomou, Alain Marenco Close preview | Related articles | Related reference w ork articlesAbstract | Figures/Tables | ReferencesAbstractA multivariate analysis methodology, applied to ozone, water vapour andpotential temperature data collected from MOZAIC aircraft allowed to identifyand to quantify three types of air masses directly linked tostratosphere-troposphere exchanges (STE). These air masses occurred inFebruary 1997 over the North Atlantic during the development of a Rossbywave, which is manifested in the form of four different structures, namelytrough, ridge, streamer and cut-off low (COL). Here a study is conducted on 20isobaric (i.e. at 230 hPa) flights crossing all these upper-level structures. It isshown that the first type of air mass corresponds to a mixed zone between thePurchase $ 35.95stratosphere and the troposphere when the tropopause is poorly defined and when there exist medium values and weak gradients of ozone, potential temperature and humidity. The second type of air mass reveals an irreversible transport from the troposphere to the stratosphere for all these structuresl eading to a ―wet‖ stratosphere with high values of water vapour. The third type of air mass corresponds to the classical stratosphere with high values of ozone and low values of water vapour. The comparison with the model results of Kowol-Santen et al. (2000) shows that these first two air masses are directly linked to either diabatic processes or turbulent diffusion depending on the orientation and the type of the structure. The western side of the trough (with no mixing zone on the eastern side) and the ridge are dominated by clear air turbulence (CAT). On the other hand, the decay of the COL seems to be the result of strong convection on its northern and eastern flanks. Concerning the decay of the streamer, it is found to be due to both diabatic and turbulent processes. The above results suggest that the existence of a mixing zone during STE seems to be a more realistic concept instead of that where the tropopause is considered as a surface.A rticle Outline1. Introduction2. The MOZAIC database3. Methodology of MA4. Evolution of a trough structure in February 19975. Air masses in the trough, ridge, COL and streamer structures5.1. The trough and ridge structures5.2. The COL structure5.3. The streamer structure6. Discussion and comparison with model result of KS007. Conclusions Acknowledgements References429 Adaptive actuator failure compensation for nonlinearMIMO systems with an aircraft controlapplication Original Research ArticleAutomatica, Volume 43, Issue 11, November 2007,Pages1869-1883Xidong Tang, Gang Tao, Suresh M. JoshiClose preview | Related articles | Related reference w ork articlesAbstract | Figures/Tables | ReferencesAbstractA direct adaptive approach is developed for control of a class of multi-inputmulti-output (MIMO) nonlinear systems in the presence of uncertain failures ofredundant actuators. An adaptive failure compensation controller is designedwhich is capable of accommodating uncertainties in actuator failure timeinstants, values and patterns. A realistic situation is studied with fixed groupingof actuators and proportional actuation within actuator groups. The adaptivecontrol system is analyzed, to show its desired stability and asymptotictracking properties in the presence of actuator failure uncertainties. As anapplication, such an adaptive controller is used for actuator failurecompensation of a twin otter aircraft longitudinal model, with design conditionsverified and control structure and adaptive laws developed for a nonlinearaircraft dynamic model. The effectiveness of adaptive failure compensation is demonstrated by simulation results.A rticle Outline1. Introduction2. Problem statementPurchase$ 35.953. Adaptive failure compensation design4. Application to aircraft flight control5. ConclusionsReferencesVitae430 An aircraft acquisition decision model under stochastic demand Original Research ArticleJournal of King Saud University - Science, In Press, Corrected Proof, Available online 28 December 2010Hooi Ling Khoo, Lay Eng TeohClose preview | PDF (445 K) | Related artic les | Related reference w orkarticlesAbstract | Figures/Tables | ReferencesAbstractThis study proposes the probabilistic dynamic programming model to address the stochastic demand issue in aircraft acquisition problem. A probable phenomena is defined to comprehend the uncertain state variables so that the targeted level of service could be achieved profitably by the airline company. The objective function and the constraints have a linear expression with respect to the decision variables, and hence the proposed model is then converted as a linear programming model. The proposed model and the solution method are then examined with an illustrative case study to determine the number and the types of new aircraft that should be purchased at every time period. The results show that the proposed methodology is viable in providing the optimal solution.A rticle Outline1. Introduction2. Nomenclature3. Problem formulation3.1. Probabilistic dynamic programming model3.1.1. Stage, state variables and optimal decision3.1.2. Constraints3.1.3. Objective function3.1.4. The probable phenomena, s 1, … , s k3.1.5.The optimization model4. Solution method5. An illustrative case study5.1. Benchmark scenario5.1.1. Other scenarios6. Results and discussion7. Conclusions References431 Aerodynamic seal for reduction of noise generated on aircraft control surfacesSealing Technology , Volume 2009, Issue 2, February2009, Page 13Close preview | Related articles | Related reference w ork articles Abstract | Figures/TablesNo abstract is available for this article. Purchase $ 31.50432 Partial substitution of hydrogen for conventional fuel in an aircraft by utilizing unused cargo compartmentspace Original Research ArticleInternational Journal of Hydrogen Energy , Volume 35,Issue 3, February 2010, Pages 1463-1473Enis T. Turgut, Marc A. Rosen Close preview | Related articles | Related reference w ork articles Abstract | Figures/Tables | ReferencesAbstractOptions are being actively sought in aviation to switch from petroleum-based fuels to alternative fuels, of which hydrogen is a promising candidate, despite challenges associated with its production and storage. The possibility is Purchase $ 31.50demonstrated in this study of using hydrogen in place of some mission fuel without making substantial aircraft modifications and while utilizing only available unused baggage space in the lower-deck cargo compartments of aircraft. The environmental impact reduction and weight increase are obtained accounting for a broad range of factors including aircraft model, seat capacity, passenger and baggage load factors, annual landing and take off cycles, container type, and costs of metal hydride and gaseous hydrogen storage units of various sizes. It is found that, while there may be a cost increase, CO2 emissions are substantially reduced, by 25,000–570,000 tonnes annually in several cases and by up to 1.1 million tonnes annually for the 10 types of aircraft considered. It is also determined that with present technology, despite the low density of hydrogen, the weight of storage systems constitutes more of a challenge than their volume in aviation. Large-body aircraft are found to have more difficulties than the narrow-body aircraft regarding storage system weight. For the most frequently used narrow- and large-body aircraft considered, the number of the available containers within the required limits of weight and volume respectively are found to be 3 and 4 for the B 737-800 aircraft and 2 and 10 for the A 340-300 aircraft. Overall, the combined usage of hydrogen and kerosene investigated here may be feasible in the future, but is a challenging option with present technology and aircraft due to various factors.A rticle OutlineNomenclature1. Introduction2. Approach3. Hydrogen storage4. Lower-deck hydrogen storage5. Results and discussion 5.1. Case study 15.2. Case study 26. ConclusionsAcknowledgementsAppendixReferencesVitae433Noise radiation of aircraft panels subjected toboundary layer pressure fluctuationsOriginal ResearchArticleJournal of Sound and Vibration, Volume 314, Issues 3-5,22 July 2008, Pages 693-711Bilong LiuClose preview | Related articles | Related reference w ork articlesAbstract | Figures/Tables | ReferencesAbstractIn this paper, a method which predicts the sound radiation of aircraft panelssubjected to turbulent boundary layer excitation is described. The method isthe extension of an earlier deterministic approach, where the modal expansionand modal receptance methods were used to predict random noisetransmission through curved aircraft panels with stringer and ring frameattachments. Here, with implementation of the Corcos and Efimtsov models tocharacterize the dynamic surface pressure cross-spectra, closed-formsolutions for the panel displacements, radiation and transmission pressuresare derived. Numerical examples are presented to illustrate the effects of thestringers, ring frames, hydrodynamic coincidence, curvature, in-plane tension,structural dissipation and composite material on the structural and acousticresponse of the panel.Purchase$ 31.50A rticle Outline1. Introduction2. TBL-induced noise for a rectangular panel with stringer attachments2.1. Governing equations and velocity response2.2. Slightly curved panels with stringer attachments2.3. The radiated power spectrum3. Numerical study3.1. Solution for a typical aircraft panel3.2. Effects of the ring frame attachments3.3. Effects of the stringer attachments3.4. Damping influence3.5. Curvature and in-plane tension influence3.6. Metallic panel vs composite panel4.Concluding remarksAcknowledgementsAppendix A. The modal excitation termsReferences434 A computational study of Benders decomposition for the integrated aircraft routing and crew schedulingproblem Original Research Article Computers & Operations Research , Volume 32, Issue 6, June 2005, Pages 1451-1476Anne Mercier, Jean-François Cordeau, François Soumis Close preview | Related articles | Related reference w ork articles Abstract | Figures/Tables | ReferencesAbstractThe integrated aircraft routing and crew scheduling problem consists indetermining a minimum-cost set of aircraft routes and crew pairings such that Purchase$ 31.50each flight leg is covered by one aircraft and one crew, and side constraints are satisfied. While some side constraints involve only crews or aircraft, linking constraints impose minimum connection times for crews that depend on aircraft connections. We propose an enhanced model incorporating robustness to handle these linking constraints and compare two Benders decomposition methods—one with the aircraft routing problem as the master problem and one with the crew pairing problem. We also study the impact of generating Pareto-optimal cuts on the speed of convergence of these methods. Computational experiments performed on test instances provided by two major airlines show that the proposed approach yields high-quality solutions in reasonable computing times.A rticle Outline0. Introduction1. Mathematical formulation1.1. Aircraft routing networks1.2. Crew pairing networks1.3. Model2. Solution methodology2.1. Benders decomposition using the crew pairing problem as a master problem2.1.1. Three-phase algorithm2.2. Identifying strong cuts2.3. Step-by-step description of the improved algorithm3. Computational experiments3.1. Description of data sets3.2. Summary of computational experiments3.3. Comparisons with the extended crew pairing approach of Cohn andBarnhart [2]4. Conclusion AcknowledgementsReferences435Sample preparation and characterization of artificiallyaged aircraft coatings for microstructuralanalysis Original Research ArticleMaterials Characterization, Volume 55, Issue 3,September 2005, Pages 179-189Lisa M. Farrier, Stephen L. SzarugaClose preview | Related articles | Related reference work articlesAbstract | Figures/Tables | ReferencesAbstractThe paper describes a method for metallographic preparation of artificiallyaged aircraft coatings. In order to better understand the in-serviceperformance and identify degradation mechanisms of an aircraft coating,complete characterization of the microstructure is essential. This paperdiscusses metallographic sample preparation and subsequent microscopytechniques (light optical microscopy, scanning electron microscopy) forcharacterization of a standard polyurethane aircraft coating system. Thepreparation method has proven to produce good, consistent results on a widerange of laboratory-produced simulated environmental exposures.The military specification coating system under study (MIL-PRF-85285C andMIL-PRF-23377G) degrades severely after accelerated weathering. Typicaldegradation includes deterioration of the polyurethane-based resin system inthe topcoat and is observed as a visible change in the color. Increasedporosity and some physical deterioration were also observed. In addition,some inorganic pigments in the primer appear to migrate into the topcoatPurchase$ 31.50during simulated exposure.A rticle Outline1. Introduction2.Experiment procedure2.1. Coating application2.2. Proposed metallographic method2.3. Method justification3. Results and discussion3.1. Microstructural characterization3.2. Free film transmissivity4. SummaryAcknowledgementsReferences436 Intelligent adaptive nonlinear flight control for a high performance aircraft with neural networksOriginal Research ArticleISA Transactions , Volume 45, Issue 2, April 2006, Pages 225-247Aydogan Savran, Ramazan Tasaltin, Yasar Becerikli Close preview | Related articles | Related reference w ork articles Abstract | ReferencesAbstractThis paper describes the development of a neural network (NN) based adaptive flight control system for a high performance aircraft. The main contribution of this work is that the proposed control system is able to compensate the system uncertainties, adapt to the changes in flightconditions, and accommodate the system failures. The underlying study can be considered in two phases. The objective of the first phase is to model the Purchase$ 31.50dynamic behavior of a nonlinear F-16 model using NNs. Therefore aNN-based adaptive identification model is developed for three angular rates of the aircraft. An on-line training procedure is developed to adapt the changes in the system dynamics and improve the identification accuracy. In thisprocedure, a first-in first-out stack is used to store a certain history of theinput-output data. The training is performed over the whole data in the stack atevery stage. To speed up the convergence rate and enhance the accuracy forachieving the on-line learning, the Levenberg-Marquardt optimization methodwith a trust region approach is adapted to train the NNs. The objective of thesecond phase is to develop intelligent flight controllers. A NN-based adaptivePID control scheme that is composed of an em ulator NN, an estimator NN,and a discrete time PID controller is developed. The emulator NN is used tocalculate the system Jacobian required to train the estimator NN. Theestimator NN, which is trained on-line by propagating the output error throughthe emulator, is used to adjust the PID gains. The NN-based adaptive PIDcontrol system is applied to control three angular rates of the nonlinear F-16model. The body-axis pitch, roll, and yaw rates are fed back via the PIDcontrollers to the elevator, aileron, and rudder actuators, respectively. Theresulting control system has learning, adaptation, and fault-tolerant abilities. Itavoids the storage and interpolation requirements for the too many controllerparameters of a typical flight control system. Performance of the controlsystem is successfully tested by performing several six-degrees-of-freedomnonlinear simulations.437An integrated aircraft routing, crew scheduling andflight retiming model Original Research ArticleComputers & Operations Research, Volume 34, Issue 8,August 2007, Pages 2251-2265Anne Mercier, François SoumisClose preview | Related articles | Related reference w ork articlesAbstract | Figures/Tables | ReferencesPurchase$ 31.50AbstractIn the integrated aircraft routing, crew scheduling and flight retiming problem, a minimum-cost set of aircraft routes and crew pairings must be constructed while choosing a departure time for each flight leg within a given time window. Linking constraints ensure that the same schedule is chosen for both the aircraft routes and the crew pairings, and impose minimum connection times for crews that depend on aircraft connections and departure times. We propose a compact formulation of the problem and a Benders decomposition method with a dynamic constraint generation procedure to solve it. Computational experiments performed on test instances provided by two major airlines show that allowing some flexibility on the departure times within an integrated model yields significant cost savings while ensuring the feasibility of the resulting aircraft routes and crew pairings.A rticle Outline0. Introduction1. Mathematical formulation1.1. Model1.2. A simpler formulation2. Solution methodology2.1. Benders decomposition2.1.1. Three-phase algorithm2.1.2. Dynamic constraint generation3. Computational experiments3.1. Description of data sets3.2. Summary of computational experiments4. ConclusionAcknowledgements References438 Low-crested coastal defence structures as artificialhabitats for marine life: Using ecological criteria indesign Original Research ArticleCoastal Engineering, Volume 52, Issues 10-11,November2005, Pages 1053-1071P.S. Moschella, M. Abbiati, P. Åberg, L. Airoldi, J.M.Anderson, F. Bacchiocchi, F. Bulleri, G.E. Dinesen, M.Frost, E. Gacia, L. Granhag, P.R. Jonsson, M.P. Satta, A.Sundelöf, R.C. Thompson, S.J. HawkinsClose preview | Related articles | Related reference w ork articlesAbstract | Figures/Tables | ReferencesAbstractCoastal defence structures to protect sedimentary coastlines from erosion andflooding are increasingly common throughout Europe. They will become more widespread over the next 10–30 years in response to rising and stormier seasand accelerating economic development of the coastal zone. Building coastaldefences results in the loss and fragmentation of sedimentary habitats andtheir replacement by artificial rocky habitats that become colonised by algaeand marine animals. The engineering design and construction of thesestructures have received considerable attention. However, the ecologicalconsequences of coastal defences have been less extensively investigated. Furthermore, due to their rapid proliferation, there is a growing need tounderstand the role of these man-made habitats in the coastal ecosystems inorder to implement impact minimisation and/or mitigation measures.As part of the DELOS project, targeted studies were carried out throughoutEurope to assess the ecological similarity of low-crested coastal defencestructures (LCS) to natural rocky shores and to investigate the influence ofLCS design features on the colonising marine epibiota. LCSs can bePurchase$ 35.95considered as a relatively poor surrogate of natural rocky shores. Epibiotic communities were qualitatively similar to those on natural rocky shores as both habitats are regulated by the same physical and biological factors. However, there were quantitative differences in the diversity and abundance of epibiota on artificial structures. Typically, epibiotic assemblages were less diverse than rocky shore communities. Also, LCSs offered less structurally complex habitats for colonisation and in some locations experienced higher disturbance than natural shores. We propose several criteria that can be integrated into the design and construction of LCSs to minimise ecological impacts and allow targeted management of diversity and natural living resources.A rticle Outline1. Introduction2. Material and methods2.1. Study sites and general methodological approach2.2. Comparison of diversity between low crested structures and natural rocky shores2.3. Effects of LCS design features on epibiotic assemblages2.3.1. Orientation2.3.2. Location on the shore2.3.3. Habitat complexity2.3.4. Disturbance: structural stability and scouring of LCS3. Results3.1. Epibiota of LCSs versus rocky shore communities3.2. Effects of LCS design features on epibiota3.2.1. Orientation3.2.2. Location on the shore (tidal height)3.2.3. Habitat complexity3.2.4. Disturbance: structural stability and scouring4. Discussion 4.1. Can LCSs be viewed as artificial rocky shores?4.2. Influence of engineering design on epibiota: what can and cannot be modified5. ConclusionsAcknowledgementsReferences439 Carbon fiber reinforced plastics in aircraft constructionOriginal Research ArticleMaterials Science and Engineering: A , Volume 412, Issues1-2, 5 December 2005, Pages 171-176 C. Soutis Show preview | Related articles | Related reference w ork articles Purchase $ 41.95440Vibration-based skin damage statistical detection and restoration assessment in a stiffened aircraftpanel Original Research Article Mechanical Systems and Signal Processing , Volume 22,Issue 2, February 2008, Pages 315-337D.D. Rizos, S.D. Fassois, Z.P. Marioli-Riga, A.N. Karanika Show preview | Related articles | Related reference w ork articlesPurchase$ 35.95 441Estimation of directivity and sound power levels emitted by aircrafts during taxiing, for outdoor noiseprediction purpose Original Research Article Applied Acoustics , Volume 68, Issue 10, October 2007, Pages 1263-1279C. Asensio, I. Pavón, M. Ruiz, R. Pagan, M. Recuero Show preview | Related articles | Related reference w ork articles Purchase$ 41.95 442Strategic planning in fractional aircraft ownership programs Original Research ArticleEuropean Journal of Operational Research , Volume 189,Issue 2, 1 September 2008, Pages 526-539Yufeng Yao, Özlem Ergun, Ellis Johnson, William Schultz, J.M. Singleton Show preview | Related articles | Related reference w ork articlesPurchase $ 31.50。

这是陈立群教授发表在力学与实践上的

刘延柱的振动力学以及R.克拉夫、J.彭津编写、王光远等校译的结构动力学第二版【全美经典】机械振动书【机器故障的分析与监测】【机械设备故障诊断技术及方法】【机械设备故障诊断技术及应用】【旋转机械振动分析与工程应用】【旋转机械振动监测及故障诊断】这些书都可以啊，网上都可以下载到，但是建议买正版的这是陈立群教授发表在力学与实践上的，对振动类书籍的评论，您可以参考一下：国外振动新教材的内容和特点振动是国内理论与应用力学专业和工程力学专业本科必修课，也是机械、土木、航空等专业本科生或研究生的选修课。

北美大学的情况基本类似，机械、土木、航空、航天和工程力学系一般都开设振动课程。

初级课程由学过工程力学(静力学和动力学)的二、三年级本科生选修，高级课程主要是研究生选修甚至必修。

土木系的初级振动课程有时也称为结构动力学，有些大学甚至是同门课程，不同的名称和编号。

据笔者所见，欧美至少出版了几十种振动教材。

本文仅讨论部分比较“新”的教材，即1995年后出版或再版的。

最新的如2006年以后出版的教材，笔者还没有仔细阅读。

另外，限于笔者外语能力，所谓“国外”教材主要是英语教材，包括欧洲大陆学者用英语出版的教材。

而且，本文不讨论没有涉及基本振动理论例如单自由度线性振动的高级课程教材。

笔者试图尽可能简要地分析各种教材在取材和处理方面的特点，并简介作者。

最后在结束语中总结这些教材及其作者的特点。

顺便一提，在20多年前笔者开始教书的时候，提到国外原版教材总有种可望不可及的感觉，既见不到，也买不起。

渐渐地情况发生变化。

首先，随着研究经费和教学项目经费的增加，原版教材变得相对便宜，一般在千元之内，可以通过外文书店向境外出版商订购。

其次，国内的图书公司引入某些教学版本，相对便宜，每册价格通常只有二、三百元。

第三，有些出版社取得外国教材的版权在境内重印发行，价格更低。

第四，有些高校购买国外期刊电子版本的同时也购买了相应出版社的书籍电子版，这种书籍虽然以专著居多，但也有少量教材。

ANSYS2020官方示例清单

技术展示：示例问题Technology Showcase: Example Problems1、Brake Squeal Analysis：制动器噪声分析解决刹车噪声问题。

重点介绍了三种分析方法：线性非预应力模态、部分非线性预应力模态和全非线性预应力模态。

该问题演示了滑动摩擦接触，并使用复特征解算器预测不稳定模态。

2、Nonlinear Analysis of a 2-D Hyperelastic Seal Using Rezoning：二维超弹性密封的重分区非线性分析用单元分裂法对二维超弹性密封组件进行了重新划分和重新划分的非线性分析。

该问题显示了如何使用多个垂直重新分区步骤来确保分析的收敛和完成。

3、Fluid-Pressure-Penetration Analysis of a Sealing System：密封系统的流体压力渗透分析分析了流体压力渗透对密封系统的影响。

使用密封主要是为了防止流体（液体、固体或气体）在两个或多个区域之间的转移。

4、Ring-Gear Forging Simulation with Rezoning：基于重分区的齿圈锻造模拟证明了在金属成形过程的二维模拟中重新分区的有效性和有用性。

重新分区有助于非线性有限元模拟的收敛性，在这种情况下，单元变形过大。

5、Delamination of a Stiffened Composite Panel Under a Compressive Load：复合材料加筋板在压缩载荷下的分层使用实体壳单元技术对分层复合结构进行建模。

该问题通过接触单元的脱粘能力来模拟界面脱层。

6、Thermal Stress Analysis of a Cooled Turbine Blade：涡轮冷却叶片的热应力分析说明如何容易地设置和执行冷却涡轮叶片的热应力分析。

该问题利用表面效应能力模拟固体区域的对流载荷，并利用一维流体流动能力获得对流载荷的高精度热解。

FLOATING HULL STRUCTURAL ANALYSIS AND DESIGN

Offshore Dynamics, Inc.
Naval Architecture, Riser Systems, Structures
Global Structural Analysis Stick Model
Stick model can be built by StruCAD
Jan 2004 Info@
Offshore Dynamics, Inc.
Naval Architecture, Riser Systems, Structures
Topsides Definition Payload/Space Requirements
Deck Size
Riser Loads Mooring Loads
Initial Hull Sizing Constraints: - Initial Stability - Motion Characteristics - Loading Conditions
•Scantling sizing is based on spreadsheet with ABS MODU/Vessel rules, API 2U, DnV MODU rules built in •Scantling sizing to be performed for plating, stiffners and girders throughout the whole platform (shell, deck, bulkhead, flat, tank, etc) for each loading conditions (operating, survival, transit, etc.)
Offshore Dynamics, Inc.

箱型梁极限弯矩简化计算方法

箱型梁极限弯矩简化计算方法冯亮;董胜;王保森;甄春博【摘要】本文采用有限元法与强度稳定综合理论(combined theory of strength and stability,CTSS)公式研究箱型梁的极限强度问题.揭示了有限元计算方法的不稳定性,结合Vasta的始屈弯矩法提出箱型梁结构的极限弯矩简化计算公式.通过两个箱型梁结构的实例计算表明,该公式的计算结果相对于试验结果的误差在10%以内,且与非线性有限元法相比有着简单、稳定的优势,可以为工程设计提供参考.%In this study, we used the finite element method and the combined theory of strength and stability (CTSS) to determine the ultimate strength of the box girder.Due to the instability of the finite element method alone, we propose a calculation formula that simplifies the ultimate bending moment of the box girder by its combination with the initial-flexion bending moment method defined by Vasta.In two calculation cases of the box girder structure, our test results show that the calculation errors associated with this formula are less than 10%.In addition, in comparison with the nonlinear finite element method, our proposed method is simple and stable, and can provide a reference for engineering design.【期刊名称】《哈尔滨工程大学学报》【年(卷),期】2017(038)003【总页数】5页(P351-355)【关键词】强度稳定综合理论;加筋板;箱型梁;极限强度;初始缺陷;有限元【作者】冯亮;董胜;王保森;甄春博【作者单位】中国海洋大学工程学院山东省海洋工程重点实验室,山东青岛266100;中国海洋大学工程学院山东省海洋工程重点实验室,山东青岛 266100;中国海洋大学工程学院山东省海洋工程重点实验室,山东青岛 266100;大连海事大学交通运输装备与海洋工程学院,辽宁大连 116026【正文语种】中文【中图分类】U661.43船体结构是典型的加筋板组合的变截面箱型梁结构，它的极限弯矩是标志其承载性能的重要指标，一直以来都受到人们的广泛重视。

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