外文翻译(中文)
结构体系抵抗水平荷载常用的结构体系在数以万计的荷载作用测量领域内,有一个不起眼的领域是进行过度复杂的高层建筑设计思想。
的确,更好地设计高层建筑的普遍特征是进行简单和清晰的表达思想。
但如果这种思想并不符合设计要求,那这种重大的思想就没有生存发展空间了。
事实上,这样一个复杂庞大的思想是由新型高层建筑家族的演进而来的。
但也许更重要的是,几年前的新概念的东西在今天早已变成司空见惯的技术了。
省略掉一些需严格遵循观念的相关联的建材,那么用于高层建筑中的最常用的结构系统可以分类如下:1.抗弯框架。
2.偏心支撑框架,包括支撑框架。
3.钢板剪力墙,包括剪力墙。
4.拉条固定管。
5.筒中筒结构。
6.核心互动结构。
7.蜂窝结构或捆绑结构。
特别是在最近这种设计潮流正在向更复杂的形式演变,但必不可少也需要增加抵抗风和地震的刚度,大多数高层建筑结构体系都建立了有支撑的组合框架,充气,剪力墙以及相关的系统。
进一步说,要想建造更高的建筑,基本都是由三维体系的互动元素组成的。
这些元素相结合的方法在本质上讲就是研究高层建筑的设计过程。
这些组合要适应环境、功能、以及成本进化的需求,从而提供有效的结构,使建筑的发展达到了一个新的高度。
这并不是说,富于想象力的结构设计能创造出伟大的建筑,相反的,有很多这样的例子,比如一些已建成的优良建筑是由一些平凡的结构工程师设计,而那些精细典雅的结构,而不是什么伟大的建筑, 也不需要具有天赋和领导才能的才华横溢的建筑师完成。
在任何情况下,这两种选择的最佳取向就是要制定一个对于高层建筑而言真正意义上的非凡设计。
通常只有在文献中才综合讨论这七个系统,而在这里有必要整体地讨论一下设计过程的本质。
1.抗弯框架也许在低到中等高度的建筑和抗弯框架中最常用的系统是在本质上具有线性水平和垂直成分的刚性连接接头系统。
使用这样的框架作为一个独立的系统或者结合其他制度等,能提供给他们最需要的抵抗水平荷载的作用。
在较高的高层建筑物中,可能就会出现一个不符合独立系统的设计, 这是因为在没有一个天赋和领导才能的才华横溢的建筑师情况下很难设计出具有足够刚度的建筑系统。
因此这两种选择的最佳取向就是要制定一个对于高层建筑而言真正意义上的非凡设计。
应力、STRUDL,或者一大堆其他的合适的电脑程序可以帮助完成分析工作;而所谓的偏门的入门分析方法在今天的技术上早已无立足之地。
由于柱或梁存在内部弹性性能,并且初步设计的目的应该是突出系统的弊端, 因此通常在初步框架分析中并不使用中心到中心模型。
当然,在之后的阶段性设计中,实际评估在联合模型中是至关重要的。
2.支撑框架支撑框架在本质上比抗弯框架的刚度更强, 并在不断增高的高层建筑中发现了更重要的应用。
这个框架系统的特征是它的线性水平、垂直和对角型构件简单或复杂地连接在接头上。
通常在更高的建筑中用于连接其他系统,在低中层建筑中作为一个独立的系统。
其次,在支撑框架混凝土框架结构中使用钢结构是很常见的,并有可能更大规模化。
更有意思的是在地震活动高发地区常使用偏心支撑框架。
再次, 应力、STRUDL,或两者之中的任何一种,或三维分析的计算机程序都可以进行分析。
而且中心到中心维度也常进行初步分析。
3.剪力墙剪力墙的出现曾经也是伴随着日益严厉结构系统进展的一步。
该系统的特点是相对较薄,通常是(但不总是)由混凝土组成,拥有提供结构强度和分隔建筑的功能。
在高层建筑中剪力墙系统往往有相对较高的高宽比,也就是说,它的墙高往往比墙宽要大很多。
若功能系统缺乏了张力,任何建筑构件在抵御系统宽度所产生的倾覆力矩和构件的重力荷载上都会受到限制。
由于受限于较小的倾覆中, 系统很显著的应用就是在建筑物很少需要窗户的外墙上拥有所需的宽度。
钢结构剪力墙一般通过具体叠加增加强度来抵抗屈曲,并经常用于剪切载荷很高的地方。
该系统本质上比钢支护系统更加经济,特别是在通过高级区域内较高的楼板来承受高剪切载荷时特别有效。
而且该系统拥有一个显著优势就是具有高延展性,在地震活动高发地区该特性就显得至关重要。
剪力墙系统的分析是很复杂的,这是由于在这些墙壁上不可避免的会有一些较大的孔洞。
初步分析可以通过桁架类比方法,或有限元方法,或利用一个专门计算机程序设计,还要考虑到剪力墙的互动和连接。
4.拉条固定管拉条固定框架或拉条固定管的概念诞生于匹兹堡IBM大楼的建筑技术中,但随即被世界贸易中心的双子星塔、纽约和许多其他建筑工程应用。
系统的特征是:用3维框架和支撑框架或剪力墙, 在一定程度上几乎没有任何计划配置自然形成一个封闭圆柱。
因为那些抗侧力柱尽可能放置在系统的角落里,因此整体的惯性矩和刚度的增加量是非常高的。
管状结构是利用三维概念或者二维空间方法分析,但不管用哪种方法,都必须能计算出剪力滞效应所造成的影响。
剪力滞效应首先发现于飞机结构检测中, 在刚度框管里那是一种严格的限制。
这个概念已将框架管的应用汇总于关于剪力的六十篇论文里。
设计师们已经开发出各种技术来减少剪力滞效应的影响,带桁架的使用最为显著。
其应用于建筑的案例高达40次甚至更高。
然而,除了可能的美学考虑,带桁架几乎使每个建筑功能与外墙的联系受到干扰;桁架往往放置在机械地板上,但机械系统设计师并不认同这一点。
然而,作为一个有效的桁架结构体系,带桁架方法非常有效,且可能会受到设计师的继续批准。
无数的研究已经优化了这些桁架的位置,而最佳的位置非常依赖于所提供的桁架数量。
经验表明,不论如何,这些桁架的位置是机械系统优化和审美考量所决定的,而在经济方面结构体系对桁架的位置并不敏感。
5.筒中筒结构管状框架体系能让每个外墙柱体抵抗弯矩和剪力。
“筒中筒”这个词在很大程度上不证自明,即双柱体环形管,整个环形周围是建筑的中心服务核心,作为一种内在框架或拉条固定管所使用。
两根管目的是提高刚度来抵抗超弯矩和侧向阻力。
两根管子的性质并不相同,其中一个起框架作用,另一个起支撑作用。
研究这一系统很重要的是去深刻理解剪力和元件弯曲挠度的不同,这是根据梁的分析情况得出的。
在框筒结构中,抗剪构件的挠度与梁柱弯曲变形有关(如下,框筒网), 同时也和抗弯构件柱的轴向伸缩有关(如下,法兰框筒)。
在一个支撑管中,抗剪构件的挠度与对角线的轴向变形有关,而抗弯构件挠度与柱体的轴向伸缩有关。
根据梁的分析,如果平面保持水平(如下,楼板),那么外管柱的轴向应力会远离中性轴,但会明显大于内管的轴向应力。
然而,在筒中筒设计中,最优条件下柱体内管轴向应力会和外管轴向应力相同甚至更高。
这个看似异常的情况是与刚性剪力构件中两个系统的差异性有关。
最简单的解释是将内管视为支撑(如下,刚性管),外观视为框架(如下,弹性管)。
6.核心互动结构核心的互动结构是筒中筒系统中的一个特殊例子,其中两支管是伴随着三维空间框架的某种形式存在。
事实上,这个系统的外管剪力通常为零。
美国匹兹堡钢结构建筑项目很好的阐明了这一系统。
在这里,内管是刚性框架,外管没有抗剪强度,但这两个系统是有关联的。
需要注意的是,如果把它们看作是一个进入“帽子”体系基础直线的系统,那么外柱会进行不恰当的模仿。
这些圆柱也许增加15%硬度来适应支撑核心的弹性屈曲。
另外,轴力与内柱侧向压缩变化有关,这种变化来自于紧张高度与拐点管,大约在试管的5 / 8的高度。
当然, 由于系统的剪力几乎为零,外柱要承受来自整个高层横向荷载的轴向力。
连接内管与外管的梁或桁架的空间结构经常位于不同级别的楼栋里。
美国电话电报公司总部就是具有惊人数组的交互式基础的一个重要例子。
(1)结构系统为94英尺(28.6m )宽,196英尺(59.7m)长,601英尺(183.3m)高。
(2)提供了两个内管,每31英尺(9.4米)追加到40英尺(12.2米),中心90 英尺(27.4m)的分离,建筑的纵向分离。
(3)内管在近端方向起支撑作用,但在近端内为零的剪切刚度在远端方向。
(4)外部套管上提供一个单一的建筑物,它环绕边界。
(5)抗弯外管是一种框架,但随着剪切刚度的中心50英尺(15.2m)各自的长边。
(6)一个空间桁架帽子结构可在大楼的顶部。
(7)一个类似的空间桁架底部附近的建筑物(8)整个组件的侧向支撑其基于双钢板剪切刚度的管子,因为在建筑的基础上外部套管的剪力趋向于零。
7.蜂窝结构蜂窝结构的一个典型例子是有由九个独立管组成的捆绑管结构的芝加哥西尔斯大厦,。
而西尔斯大厦由9个近乎相同的管组成,基础结构体系对形状不规则的建筑物有特殊的用处,由于几个管外型上不需要有相似的规划模型,一些独立的管就突出了系统的许多优劣之处,这种情况很常见。
由于系统的这种特殊的弱点,尤其是框管,因此必须有处理这种微分柱缩短的观念。
这种在荷载作用下的缩短,可利用利用该表达式计算:△=ΣfL/E对建筑物来说,12英尺(3.66m)和15克耐思(138Mpa)天棚平均压应力缓解一列在荷载作用下的应力,是每15(12)(12)/ 29000或0.074in(1.9mm)。
在50篇论文里,柱体已被缩短为3.7(94mm),低于其无应力的长度。
对于一个蜂窝式的绑管系统而言,其高度为50stories,而相邻蜂窝式系统其高度为100stories,那些临近两个系统边界线之间的柱体就需要调整一下微分挠度了。
主体结构工作需要在一些特定的地点完成。
在墨尔本里亚尔托项目至少有一个建筑中,结构工程师发现必须降低垂直预应力柱的高度以便协调承受短柱后加拉力的柱体的微分挠度,同时这种短柱也增加了临近的更高的柱体的重量。
外文参考文献翻译-中文
外⽂参考⽂献翻译-中⽂基于4G LTE技术的⾼速铁路移动通信系统KS Solanki教授,Kratika ChouhanUjjain⼯程学院,印度Madhya Pradesh的Ujjain摘要:随着时间发展,⾼速铁路(HSR)要求可靠的,安全的列车运⾏和乘客通信。
为了实现这个⽬标,HSR的系统需要更⾼的带宽和更短的响应时间,⽽且HSR的旧技术需要进⾏发展,开发新技术,改进现有的架构和控制成本。
为了满⾜这⼀要求,HSR采⽤了GSM的演进GSM-R技术,但它并不能满⾜客户的需求。
因此采⽤了新技术LTE-R,它提供了更⾼的带宽,并且在⾼速下提供了更⾼的客户满意度。
本⽂介绍了LTE-R,给出GSM-R与LTE-R之间的⽐较结果,并描述了在⾼速下哪种铁路移动通信系统更好。
关键词:⾼速铁路,LTE,GSM,通信和信令系统⼀介绍⾼速铁路需要提⾼对移动通信系统的要求。
随着这种改进,其⽹络架构和硬件设备必须适应⾼达500公⾥/⼩时的列车速度。
HSR还需要快速切换功能。
因此,为了解决这些问题,HSR 需要⼀种名为LTE-R的新技术,基于LTE-R的HSR提供⾼数据传输速率,更⾼带宽和低延迟。
LTE-R能够处理⽇益增长的业务量,确保乘客安全并提供实时多媒体信息。
随着列车速度的不断提⾼,可靠的宽带通信系统对于⾼铁移动通信⾄关重要。
HSR的应⽤服务质量(QOS)测量,包括如数据速率,误码率(BER)和传输延迟。
为了实现HSR的运营需求,需要⼀个能够与 LTE保持⼀致的能⼒的新系统,提供新的业务,但仍能够与GSM-R长时间共存。
HSR系统选择合适的⽆线通信系统时,需要考虑性能,服务,属性,频段和⼯业⽀持等问题。
4G LTE系统与第三代(3G)系统相⽐,它具有简单的扁平架构,⾼数据速率和低延迟。
在LTE的性能和成熟度⽔平上,LTE- railway(LTE-R)将可能成为下⼀代HSR通信系统。
⼆ LTE-R系统描述考虑LTE-R的频率和频谱使⽤,对为⾼速铁路(HSR)通信提供更⾼效的数据传输⾮常重要。
外文翻译中英文对照
Strengths优势All these private sector banks hold strong position on CRM part, they have professional, dedicated and well-trained employees.所以这些私人银行在客户管理部分都持支持态度,他们拥有专业的、细致的、训练有素的员工。
Private sector banks offer a wide range of banking and financial products and financial services to corporate and retail customers through a variety of delivery channels such as ATMs, Internet-banking, mobile-banking, etc. 私有银行通过许多传递通道(如自动取款机、网上银行、手机银行等)提供大范围的银行和金融产品、金融服务进行合作并向客户零售。
The area could be Investment management banking, life and non-life insurance, venture capital and asset management, retail loans such as home loans, personal loans, educational loans, car loans, consumer durable loans, credit cards, etc. 涉及的领域包括投资管理银行、生命和非生命保险、风险投资与资产管理、零售贷款(如家庭贷款、个人贷款、教育贷款、汽车贷款、耐用消费品贷款、信用卡等)。
Private sector banks focus on customization of products that are designed to meet the specific needs of customers. 私人银行主要致力于为一些特殊需求的客户进行设计和产品定制。
毕业论文外文翻译(中英文)
译文交通拥堵和城市交通系统的可持续发展摘要:城市化和机动化的快速增长,通常有助于城市交通系统的发展,是经济性,环境性和社会可持续性的体现,但其结果是交通量无情增加,导致交通拥挤。
道路拥挤定价已经提出了很多次,作为一个经济措施缓解城市交通拥挤,但还没有见过在实践中广泛使用,因为道路收费的一些潜在的影响仍然不明。
本文首先回顾可持续运输系统的概念,它应该满足集体经济发展,环境保护和社会正义的目标.然后,根据可持续交通系统的特点,使拥挤收费能够促进经济增长,环境保护和社会正义。
研究结果表明,交通拥堵收费是一个切实有效的方式,可以促进城市交通系统的可持续发展。
一、介绍城市交通是一个在世界各地的大城市迫切关注的话题。
随着中国的城市化和机动化的快速发展,交通拥堵已成为一个越来越严重的问题,造成较大的时间延迟,增加能源消耗和空气污染,减少了道路网络的可靠性.在许多城市,交通挤塞情况被看作是经济发展的障碍.我们可以使用多种方法来解决交通挤塞,包括新的基础设施建设,改善基础设施的维护和操作,并利用现有的基础设施,通过需求管理策略,包括定价机制,更有效地减少运输密度.交通拥堵收费在很久以前就已提出,作为一种有效的措施,来缓解的交通挤塞情况。
交通拥堵收费的原则与目标是通过对选择在高峰拥挤时段的设施的使用实施附加收费,以纾缓拥堵情况.转移非高峰期一些出行路线,远离拥挤的设施或高占用车辆,或完全阻止一些出行,交通拥堵收费计划将在节省时间和降低经营成本的基础上,改善空气中的质量,减少能源消耗和改善过境生产力。
此计划在世界很多国家和地方都有成功的应用。
继在20世纪70年代初和80年代中期挪威与新加坡实行收费环,在2003年2月伦敦金融城推出了面积收费;直至现在,它都是已经开始实施拥挤收费的大都市圈中一个最知名的例子。
然而,交通拥堵收费由于理论和政治的原因未能在实践中广泛使用。
道路收费的一些潜在的影响尚不清楚,和城市发展的拥塞定价可持续性,需要进一步研究。
本科毕业设计外文翻译(中文)
本科生毕业设计(论文)外文翻译外文原文题目:Real-time interactive optical micromanipulation of a mixture of high- and low-index particles中文翻译题目:高低折射率微粒混合物的实时交互式光学微操作毕业设计(论文)题目:阵列光镊软件控制系统设计姓名:任有健学院:生命学院班级:06210501指导教师:李勤高低折射率微粒混合物的实时交互式光学微操作Peter John Rodrigo Vincent Ricardo Daria Jesper Glückstad丹麦罗斯基勒DK-4000号,Risø国家实验室光学和等离子研究系jesper.gluckstad@risoe.dkhttp://www.risoe.dk/ofd/competence/ppo.htm摘要:本文论证一种对于胶体的实时交互式光学微操作的方法,胶体中包含两种折射率的微粒,与悬浮介质(0n )相比,分别低于(0L n n <)、高于(0H n n >)悬浮介质的折射率。
球形的高低折射率微粒在横平板上被一批捕获激光束生成的约束光势能捕获,捕获激光束的横剖面可以分为“礼帽形”和“圆环形”两种光强剖面。
这种应用方法在光学捕获的空间分布和个体几何学方面提供了广泛的可重构性。
我们以实验为基础证实了同时捕获又独立操作悬浮于水(0 1.33n =)中不同尺寸的球形碳酸钠微壳( 1.2L n ≈)和聚苯乙烯微珠( 1.57H n =)的独特性质。
©2004 美国光学学会光学分类与标引体系编码:(140.7010)捕获、(170.4520)光学限制与操作和(230.6120)空间光调制器。
1 引言光带有动量和角动量。
伴随于光与物质相互作用的动量转移为我们提供了在介观量级捕获和操作微粒的方法。
过去数十年中的巨大发展已经导致了在生物和物理领域常规光学捕获的各种应用以及下一代光学微操作体系的出现[1-5]。
岩土工程中英文对照外文翻译文献
中英文对照外文翻译(文档含英文原文和中文翻译)原文:Safety Assurance for Challenging Geotechnical Civil Engineering Constructions in Urban AreasAbstractSafety is the most important aspect during design, construction and service time of any structure, especially for challenging projects like high-rise buildings and tunnels in urban areas. A high level design considering the soil-structure interaction, based on a qualified soil investigation is required for a safe and optimised design. Dueto the complexity of geotechnical constructions the safety assurance guaranteed by the 4-eye-principle is essential. The 4-eye-principle consists of an independent peer review by publicly certified experts combined with the observational method. The paper presents the fundamental aspects of safety assurance by the 4-eye-principle. The application is explained on several examples, as deep excavations, complex foundation systems for high-rise buildings and tunnel constructions in urban areas. The experiences made in the planning, design and construction phases are explained and for new inner urban projects recommendations are given.Key words: Natural Asset; Financial Value; Neural Network1.IntroductionA safety design and construction of challenging projects in urban areas is based on the following main aspects:Qualified experts for planning, design and construction;Interaction between architects, structural engineers and geotechnical engineers;Adequate soil investigation;Design of deep foundation systems using the FiniteElement-Method (FEM) in combination with enhanced in-situ load tests for calibrating the soil parameters used in the numerical simulations;Quality assurance by an independent peer review process and the observational method (4-eye-principle).These facts will be explained by large construction projects which are located in difficult soil and groundwater conditions.2.The 4-Eye-PrincipleThe basis for safety assurance is the 4-eye-principle. This 4-eye-principle is a process of an independent peer review as shown in Figure 1. It consists of 3 parts. The investor, the experts for planning and design and the construction company belong to the first division. Planning and design are done accordingto the requirements of the investor and all relevant documents to obtain the building permission are prepared. The building authorities are the second part and are responsible for the buildingpermission which is given to the investor. The thirddivision consists of the publicly certified experts.They are appointed by the building authorities but work as independent experts. They are responsible for the technical supervision of the planning, design and the construction.In order to achieve the license as a publicly certified expert for geotechnical engineering by the building authorities intensive studies of geotechnical engineering in university and large experiences in geotechnical engineering with special knowledge about the soil-structure interaction have to be proven.The independent peer review by publicly certified experts for geotechnical engineering makes sure that all information including the results of the soil investigation consisting of labor field tests and the boundary conditions defined for the geotechnical design are complete and correct.In the case of a defect or collapse the publicly certified expert for geotechnical engineering can be involved as an independent expert to find out the reasons for the defect or damage and to develop a concept for stabilization and reconstruction [1].For all difficult projects an independent peer review is essential for the successful realization of the project.3.Observational MethodThe observational method is practical to projects with difficult boundary conditions for verification of the design during the construction time and, if necessary, during service time. For example in the European Standard Eurocode 7 (EC 7) the effect and the boundary conditions of the observational method are defined.The application of the observational method is recommended for the following types of construction projects [2]:very complicated/complex projects;projects with a distinctive soil-structure-interaction,e.g. mixed shallow and deep foundations, retaining walls for deep excavations, Combined Pile-Raft Foundations (CPRFs);projects with a high and variable water pressure;complex interaction situations consisting of ground,excavation and neighbouring buildings and structures;projects with pore-water pressures reducing the stability;projects on slopes.The observational method is always a combination of the common geotechnical investigations before and during the construction phase together with the theoretical modeling and a plan of contingency actions(Figure 2). Only monitoring to ensure the stability and the service ability of the structure is not sufficient and,according to the standardization, not permitted for this purpose. Overall the observational method is an institutionalized controlling instrument to verify the soil and rock mechanical modeling [3,4].The identification of all potential failure mechanismsis essential for defining the measure concept. The concept has to be designed in that way that all these mechanisms can be observed. The measurements need to beof an adequate accuracy to allow the identification ocritical tendencies. The required accuracy as well as the boundary values need to be identified within the design phase of the observational method . Contingency actions needs to be planned in the design phase of the observational method and depend on the ductility of the systems.The observational method must not be seen as a potential alternative for a comprehensive soil investigation campaign. A comprehensive soil investigation campaignis in any way of essential importance. Additionally the observational method is a tool of quality assurance and allows the verification of the parameters and calculations applied in the design phase. The observational method helps to achieve an economic and save construction [5].4.In-Situ Load TestOn project and site related soil investigations with coredrillings and laboratory tests the soil parameters are determined. Laboratory tests are important and essential for the initial definition of soil mechanical properties of the soil layer, but usually not sufficient for an entire and realistic capture of the complex conditions, caused by theinteraction of subsoil and construction [6].In order to reliably determine the ultimate bearing capacity of piles, load tests need to be carried out [7]. Forpile load tests often very high counter weights or strong anchor systems are necessary. By using the Osterberg method high loads can be reached without install inganchors or counter weights. Hydraulic jacks induce the load in the pile using the pile itself partly as abutment.The results of the field tests allow a calibration of the numerical simulations.The principle scheme of pile load tests is shown in Figure 3.5.Examples for Engineering Practice5.1. Classic Pile Foundation for a High-Rise Building in Frankfurt Clay and LimestoneIn the downtown of Frankfurt am Main, Germany, on aconstruction site of 17,400 m2 the high-rise buildingproject “PalaisQuartier” has been realized (Figure 4). The construction was finished in 2010.The complex consists of several structures with a total of 180,000 m2 floor space, there of 60,000 m2 underground (Figure 5). The project includes the historic building “Thurn-und Taxis-Palais” whose facade has been preserved (Unit A). The office building (Unit B),which is the highest building of the project with a height of 136 m has 34 floors each with a floor space of 1340 m2. The hotel building (Unit C) has a height of 99 m with 24 upper floors. The retail area (Unit D)runs along the total length of the eastern part of the site and consists of eight upper floors with a total height of 43 m.The underground parking garage with five floors spans across the complete project area. With an 8 m high first sublevel, partially with mezzanine floor, and four more sub-levels the foundation depth results to 22 m below ground level. There by excavation bottom is at 80m above sea level (msl). A total of 302 foundation piles(diameter up to 1.86 m, length up to 27 m) reach down to depths of 53.2 m to 70.1 m. above sea level depending on the structural requirements.The pile head of the 543 retaining wall piles (diameter1.5 m, length up to 38 m)were located between 94.1 m and 99.6 m above sea level, the pile base was between 59.8 m and 73.4 m above sea level depending on the structural requirements. As shown in the sectional view(Figure 6), the upper part of the piles is in the Frankfurt Clay and the base of the piles is set in the rocky Frankfurt Limestone.Regarding the large number of piles and the high pile loads a pile load test has been carried out for optimization of the classic pile foundation. Osterberg-Cells(O-Cells) have been installed in two levels in order to assess the influence of pile shaft grouting on the limit skin friction of the piles in the Frankfurt Limestone(Figure 6). The test pile with a total length of 12.9 m and a diameter of 1.68 m consist of three segments and has been installed in the Frankfurt Limestone layer 31.7 m below ground level. The upper pile segment above the upper cell level and the middle pile segment between the two cell levels can be tested independently. In the first phase of the test the upper part was loaded by using the middle and the lower part as abutment. A limit of 24 MN could be reached (Figure 7). The upper segment was lifted about 1.5 cm, the settlement of the middle and lower part was 1.0 cm. The mobilized shaft friction was about 830 kN/m2.Subsequently the upper pile segment was uncoupled by discharging the upper cell level. In the second test phase the middle pile segment was loaded by using the lower segment as abutment. The limit load of the middle segment with shaft grouting was 27.5 MN (Figure 7).The skin friction was 1040 kN/m2, this means 24% higher than without shaft grouting. Based on the results of the pile load test using O-Cells the majority of the 290 foundation piles were made by applying shaft grouting. Due to pile load test the total length of was reduced significantly.5.2. CPRF for a High-Rise Building in Clay MarlIn the scope of the project Mirax Plaza in Kiev, Ukraine,2 high-rise buildings, each of them 192 m (46 storeys)high, a shopping and entertainment mall and an underground parking are under construction (Figure 8). The area of the project is about 294,000 m2 and cuts a 30 m high natural slope.The geotechnical investigations have been executed 70m deep. The soil conditions at the construction site are as follows: fill to a depth of 2 m to 3mquaternary silty sand and sandy silt with a thickness of 5 m to 10 m tertiary silt and sand (Charkow and Poltaw formation) with a thickness of 0 m to 24 m tertiary clayey silt and clay marl of the Kiev and But schak formation with a thickness of about 20 m tertiary fine sand of the But schak formation up to the investigation depthThe ground water level is in a depth of about 2 m below the ground surface. The soil conditions and a cross section of the project are shown in Figure 9.For verification of the shaft and base resistance of the deep foundation elements and for calibration of the numerical simulations pile load tests have been carried out on the construction yard. The piles had a diameter of 0.82 m and a length of about 10 m to 44 m. Using the results of the load tests the back analysis for verification of the FEM simulations was done. The soil properties in accordance with the results of the back analysis were partly 3 times higher than indicated in the geotechnical report. Figure 10 shows the results of the load test No. 2 and the numerical back analysis. Measurement and calculation show a good accordance.The obtained results of the pile load tests and of the executed back analysis were applied in 3-dimensionalFEM-simulations of the foundation for Tower A, taking advantage of the symmetry of the footprint of the building. The overall load of the Tower A is about 2200 MN and the area of the foundation about 2000 m2 (Figure11).The foundation design considers a CPRF with 64 barrettes with 33 m length and a cross section of 2.8 m × 0.8m. The raft of 3 m thickness is located in Kiev Clay Marl at about 10 m depth below the ground surface. The barrettes are penetrating the layer of Kiev Clay Marl reaching the Butschak Sands.The calculated loads on the barrettes were in the range of 22.1 MN to 44.5 MN. The load on the outer barrettes was about 41.2 MN to 44.5 MN which significantly exceeds the loads on the inner barrettes with the maximum value of 30.7 MN. This behavior is typical for a CPRF.The outer deep foundation elements take more loads because of their higher stiffness due to the higher volume of the activated soil. The CPRF coefficient is 0.88 =CPRF . Maximum settlements of about 12 cm werecalculated due to the settlement-relevant load of 85% of the total design load. The pressure under the foundation raft is calculated in the most areas not exceeding 200 kN/m2, at the raft edge the pressure reaches 400 kN/m2.The calculated base pressure of the outer barrettes has anaverage of 5100 kN/m2 and for inner barrettes an average of 4130 kN/m2. The mobilized shaft resistance increases with the depth reaching 180 kN/m2 for outer barrettes and 150 kN/m2 for inner barrettes.During the construction of Mirax Plaza the observational method according to EC 7 is applied. Especially the distribution of the loads between the barrettes and the raft is monitored. For this reason 3 earth pressure devices were installed under the raft and 2 barrettes (most loaded outer barrette and average loaded inner barrette) were instrumented over the length.In the scope of the project Mirax Plaza the new allowable shaft resistance and base resistance were defined for typical soil layers in Kiev. This unique experience will be used for the skyscrapers of new generation in Ukraine.The CPRF of the high-rise building project MiraxPlaza represents the first authorized CPRF in the Ukraine. Using the advanced optimization approaches and taking advantage of the positive effect of CPRF the number of barrettes could be reduced from 120 barrettes with 40 mlength to 64 barrettes with 33 m length. The foundation optimization leads to considerable decrease of the utilized resources (cement, aggregates, water, energy etc.)and cost savings of about 3.3 Million US$.译文:安全保证岩土公民发起挑战工程建设在城市地区摘要安全是最重要的方面在设计、施工和服务时间的任何结构,特别是对具有挑战性的项目,如高层建筑和隧道在城市地区。
消费者行为心理学中英文外文文献翻译
消费者行为心理学中英文外文文献翻译(含:英文原文及中文译文)英文原文Frontiers of Social PsychologyArie W. Kruglanski 、Joseph P. ForgasFrontiers of Social Psychology is a new series of domain-specific handbooks. The purpose of each volume is to provide readers with a cutting-edge overview of the most recent theoretical, methodological, and practical developments in a substantive area of social psychology, in greater depth than is possible in general social psychology handbooks. The editors and contributors are all internationally renowned scholars whose work is at the cutting-edge of research.Scholarly, yet accessible, the volumes in the Frontiers series are an essential resource for senior undergraduates, postgraduates, researchers, and practitioners, and are suitable as texts in advanced courses in specific subareas of social psychology.Some Social Asp ects of Living in a Consumer SocietyThe following sketches will illustrate that in a consumer society much of the behavior studied by social psychologists relates to consumer stimuli and consumer behavior. Thus, the consumer context provides a rich field for the study of social phenomena and behavior.Consumer Decisions Are UbiquitousWhether we are in the supermarket or not, we are constantly making consumer decisions. We enroll in gyms, use our frequent-flyer miles for a vacation resort, buy health care, choose a restaurant, skip dessert for a healthier lifestyle. In fact, most of our daily decisions do not involve existential decisions such as whom to marry or whether to have children or not, but whether to have tea or coffee, use our credit card or pay cash, or other seemingly trivial decisions. Moreover, many of our daily (consumer) behaviors do not even require intentional decisions. Rather, they may be habitual, such as switching to CNN to get the news or accessing Google when looking up some information. A typical day of a typical person is filled with countless minor consumer decisions or the consequences of previous decisions, starting with the brand of toothpaste in the morning to choosing a movie after work.Consumer Choices Fulfill a Social-Identity FunctionAlthough for most people being a consumer may not be central to their identity, many of their consumer decisions are nevertheless highly identity-relevant insofar as they correspond to a larger set of values and beliefs and express important aspects of the self. Eating a vegetarian diet because one does not want to endorse cruelty to animals and boycotting clothes potentially made by child laborers are some examples. Some people buy a Prius out of environmental concerns; others boycott Japanese cars —such as the Prius —in order to help the local carindustry. In this respect, even the choice between Coke and Pepsi is not necessarily trivial. People who cannot discriminate Coke from Pepsi in a blind test, or who prefer Pepsi, may nevertheless adhere to Coke as a cultural icon. Attempts to change the formula of Coke met with angry protests and opposition. Clearly, consumer products and brands do not only fulfill utilitarian needs (Olson & Mayo, 2000; Shavitt, 1990). In a world of oversupply and differentiating brands, many consumers choose brands in order to express their personality or to affiliate themselves with desired others. They do not simply use a Mac; they are Mac users, and switching to another brand of PC would be akin to treason. From soft drinks to computers, brands may become an ideology. People may also perceive of products as extended selves (Belk, 1988); for example, they may identify with their cars just as they do with pets. Likewise, brands may define social groups. The Harley-Davidson Club is a legendary example; an Internet search revealed clubs for almost every car brand and model. In my hometown, I found a V olkswagen New Beetle Club whose stated purpose is to cultivate contacts between New Beetle Drivers by organizing social events (among others, a visit to a car cemetery). On the road, drivers of the same car model often greet each other. Apparently, driving the same model is sufficient to establish social closeness. Brands, products, and consumption habits not only help to establish social connectivity but also serve as status symbols, defining vertical andhorizontal social boundaries. By using particular brands or consuming specific products, people can express a certain lifestyle or attempt to convey a particular social impression. Subscribing to the opera conveys one’s social position just as going to a monster truck race does. Whether your choice of drink is wine or beer, cappuccino or herbal tea, your order expresses more than merely your taste in beverages.Consumer Choices Affect Social PerceptionGiven that brands and products are part of social expression, it is not surprising that people are judged by the brands and products they use. In particular, products of a social-identity function are used as bases for inferences about a target’s personality traits (Shavitt & Nelson, 2000). Likewise, smoking, food choice and amount of food intake have all been shown to affect social impressions. Depending on the subculture of the perceiver (age, country), different personality traits are assumed in smokers compared with nonsmokers (e.g., Cooper & Kohn, 1989; Jones & Carroll, 1998). Various studies found that eaters of a healthier diet are perceived as more feminine and in general judged more favorably than eaters of unhealthy foods (for a review see V artanian, Herman, & Polivy, 2007). Arguing that a Pepsi drinker is to a Coke drinker what a Capulet was to a Montague is, of course, an exaggeration, but clearly brands may distinguish ingroup from out-group members. Possibly this is most extreme among teenagers, where the brand of jeans is perceived todetermine coolness and popularity. Nevertheless, the phenomenon is not limited to teen culture, as testified by the previous examples of social communities defined by shared brands. In sum, from wet versus dry shaving to driving a Porsche versus a Smart, consumer behavior is used as a cue in person perception. Most likely, such cues also manifest in behavior toward these consumers. Physical attacks on women who wear fur are a most extreme example.Affective Consequences of Consumer BehaviorObviously, consumption and the use of products and services may give pleasure and satisfaction or displeasure and dissatisfaction. People may experience joy from wearing a new sweater or suffer emotional consequences when products or services fail or cause inconvenience. Product use is only one source of affective consumer experiences. The mere act of choosing and acquisition is another. People enjoy or dislike the experience of shopping. They may take pleasure from the freedom of simply choosing between different options (e.g., Botti & Iyengar, 2004), feel overwhelmed and confused by an abundance of options (e.g., Huffman & Kahn, 1998), or feel frustrated by a limited assortment that does not meet their particular needs (e.g., Chernev, 2003). They may experience gratification and a boost in self-esteem from the fact that they can afford a particular consumer lifestyle or grudge the fact that they cannot. Many daily sources of affective experiences involve consumerbehavior in one way or another.The Consumer Context Provides Unique Social InteractionsGranted, we rarely form deep and meaningful relationships with our hairdressers and waiters. Still, the consumer context affords many social interactions over a day. Again, these interactions— even if brief— may constitute a source of affective experiences. The smile of the barista, the compliment from the shop-assistant, and the friendly help from the concierge are just a few examples of how such consumerrelated interactions may make us feel good, worthy, and valued, whereas snappy and rude responses have the opposite effect. Besides, the social roles defined by the consumer context may provide unique opportunities for particular behaviors, interactions, and experiences not inherent in other roles. Being a client or customer makes one expect respect, courtesy, and attendance to one’s needs. For some, this may be the only role in their life that gives them a limited sense of being in charge and having others meet their demands. To give another example, complaining is a form of social interaction that mostly takes place within the consumer context. A search for ―complaint behavior‖ in the PsycI NFO database found that 34 out of 50 entries were studies from the consumer context. (The rest mostly related to health care, which may to some extent also be viewed as consumer context.) Given the importance of the consumer context to social experiences and interactions, it provides a prime opportunity forstudying these social behaviors.•How consumers think, feel, reason, and the psychology of screening for different items (such as brands, products); • Consumer behavior when they shop or make other marketing decisions;•Limits in consumer knowledge or access to information affect decisions and marketing outcomes;•How can marketers adapt and improve their marketing competitiveness and marketing strategies to attract consumers more efficiently?Bergi gives an official definition of consumer behavior: the process and the activities people perform when they research, select, purchase, use, evaluate, and deal with products and services in order to meet their needs. The behavior occurs in a group or an organization where individuals or individuals appear in this context. Consumer behavior includes using and handling products and studying how products are bought. The use of products is generally of great interest to marketers because it may affect how a product is in the best position or how we can encourage increased consumption.The Nicosia model focuses on the relationship between the company and its potential customers. The company communicates with consumers through its marketing messages or advertisements and consumers' reactions to the information they want to buy. Seeing this pattern, we willfind that companies and consumers are interconnected. Companies want to influence consumers. Consumers influence company decisions through their decisions.Consumer sentiment refers to a unique set of emotional reactions to the use of or eliciting a consumer experience in the product, a unique class or relationship of the emotional experience described and expressed (such as joy, anger and fear), such as the structural dimensions of the emotional category or pleasant/unpleasant, Relax/action, or calm/excited. Goods and services are often accompanied by emotional reactions (such as the fear caused by watching a horror movie). Emotional values are often associated with aesthetic choices (such as religion, reason). However, more material and utilitarian products also seem to have emotional value. For example, some foods cause childhood experiences and feel comfortable with them. Izad (1977) developed a method of emotional experience and introduced basic emotions. He uses ten words to distinguish the basic types of emotions: interest, joy, surprise, sadness, anger, disgust, contempt, fear, shame, and guilt. This method has been widely used by consumer research.In order to implement the interpersonal and personal construction in this framework, we use the concept of self-awareness to express the influence of consumer response on society. Self-awareness is defined as the individual's consistent trend to focus directly on inward or outward.This theory identifies two different types of people with self-consciousness. The open self-conscious person pays special attention to other people's views on their outside. The private self-conscious person pays more attention to their inner thoughts and feelings. In this case, we assume that the reputation of consumption may be different based on sensitivity to other people. This proposal is also consistent with previous research. It shows that people with different personal behaviors depend on their sensitivity to interpersonal influences. Dubois and Dikena emphasized that "we believe that the analysis of the direct relationship between consumers and brands is a key to improving understanding of such a market." This original assumption is that of private or The value of the open superior product comes from the inherent social status of these objects. Many existing studies emphasize the role of the role played in the exchange of information about their owners and social relationships.中文译文社会心理学前沿艾瑞·克鲁格兰斯基,约瑟夫·弗加斯社会心理学的前沿是一个新的领域专用手册系列。
(完整版)外文翻译
外文文献原稿和译文原稿logistics distribution center location factors:(1) the goods distribution and quantity. This is the distribution center and distribution of the object, such as goods source and the future of distribution, history and current and future forecast and development, etc. Distribution center should as far as possible and producer form in the area and distribution short optimization. The quantity of goods is along with the growth of the size distribution and constant growth. Goods higher growth rate, the more demand distribution center location is reasonable and reducing conveying process unnecessary waste.(2) transportation conditions. The location of logistics distribution center should be close to the transportation hub, and to form the logistics distribution center in the process of a proper nodes. In the conditional, distribution center should be as close to the railway station, port and highway.(3) land conditions. Logistics distribution center covers an area of land in increasingly expensive problem today is more and more important. Is the use of the existing land or land again? Land price? Whether to conform to the requirements of the plan for the government, and so on, in the construction distribution center have considered.(4) commodities flow. Enterprise production of consumer goods as the population shift and change, should according to enterprise's better distribution system positioning. Meanwhile, industrial products market will transfer change, in order to determine the raw materials and semi-finished products of commodities such as change of flow in the location of logistics distribution center should be considered when the flow of the specific conditions of the relevant goods.(5) other factors. Such as labor, transportation and service convenience degree, investment restrictions, etc.How to reduce logistics cost,enhance the adaptive capacity and strain capacity of distribution center is a key research question of agricultural product logistics distribution center.At present,most of the research on logistics cost concentrates off theoretical analysis of direct factors of logistics cost, and solves the problem of over-high logistics Cost mainly by direct channel solution.This research stresses on the view of how to loeate distribution center, analyzes the influence of locating distribution center on logistics cost.and finds one kind of simple and easy location method by carrying on the location analysis of distribution center through computer modeling and the application of Exeel.So the location of agricultural product logistics distribution center can be achieved scientifically and reasonably, which will attain the goal of reducing logistics cost, and have a decision.making support function to the logisties facilities and planning of agricultural product.The agricultural product logistics distribution center deals with dozens and even hundreds of clients every day, and transactions are made in high-frequency. If the distribution center is far away from other distribution points,the moving and transporting of materials and the collecting of operational data is inconvenient and costly. costly.The modernization of agricultural product logistics s distribution center is a complex engineering system,not only involves logistics technology, information technology, but also logistics management ideas and its methods,in particular the specifying of strategic location and business model is essential for the constructing of distribution center. How to reduce logistics cost,enhance the adaptive capacity and strain capacity of distribution center is a key research question of agricultural product logistics distribution center. The so—called logistics costs refers to the expenditure summation of manpower, material and financial resources in the moving process of the goods.such as loading and unloading,conveying,transport,storage,circulating,processing, information processing and other segments. In a word。
建筑防火中英文对照外文翻译文献
- 1 -中英文对照外文翻译(文档含英文原文和中文翻译)外文文献外文文献: :Designing Against Fire Of BulidingABSTRACT:This paper considers the design of buildings for fire safety. It is found that fire and the associ- ated effects on buildings is significantly different to other forms of loading such as gravity live loads, wind and earthquakes and their respective effects on the building structure. Fire events are derived from the human activities within buildings or from the malfunction of mechanical and electrical equipment provided within buildings to achieve a serviceable environment. It is therefore possible to directly influence the rate of fire starts within buildings by changing human behaviour, improved maintenance and improved design of mechanical and electricalsystems. Furthermore, should a fire develops, it is possible to directly influence the resulting fire severity by the incorporation of fire safety systems such as sprinklers and to provide measures within the building to enable safer egress from the building. The ability to influence the rate of fire starts and the resulting fire severity is unique to the consideration of fire within buildings since other loads such as wind and earthquakes are directly a function of nature. The possible approaches for designing a building for fire safety are presented using an example of a multi-storey building constructed over a railway line. The design of both the transfer structure supporting the building over the railway and the levels above the transfer structure are consideredin the context of current regulatory requirements. The principles and assumptions associ- ated with various approaches are discussed.1 INTRODUCTIONOther papers presented in this series consider the design of buildings for gravity loads, wind and earthquakes.The design of buildings against such load effects is to a large extent covered by engineering based standards referenced by the building regulations. This is not the case, to nearly the same extent, in the case of fire. Rather, it is building regulations such as the Building Code of Australia (BCA) that directly specify most of the requirements for fire safety of buildings with reference being made to Standards such as AS3600 or AS4100 for methods for determining the fire resistance of structural elements.The purpose of this paper is to consider the design of buildings for fire safety from an engineering perspective (as is currently done for other loads such as wind or earthquakes), whilst at the same time,putting such approaches in the context of the current regulatory requirements.At the outset,it needs to be noted that designing a building for fire safety is far more than simply considering the building structure and whether it has sufficient structural adequacy.This is because fires can have a direct influence on occupants via smoke and heat and can grow in size and severity unlike other effects imposed on the building. Notwithstanding these comments, the focus of this paper will be largely on design issues associated with the building structure.Two situations associated with a building are used for the purpose of discussion. The multi-storey office building shown in Figure 1 is supported by a transfer structure that spans over a set of railway tracks. It is assumed that a wide range of rail traffic utilises these tracks including freight and diesel locomotives. The first situation to be considered from a fire safety perspective is the transfer structure.This is termed Situation 1 and the key questions are: what level of fire resistance is required for this transfer structure and how can this be determined? This situation has been chosen since it clearly falls outside the normal regulatory scope of most build-ing regulations. An engineering solution, rather than a prescriptive one is required. The second fire situation (termed Situation 2) corresponds to a fire within the office levels of the building and is covered by building regulations. This situation is chosen because it will enable a discussion of engineering approaches and how these interface with the building regulations regulations––since both engineering and prescriptive solutions are possible.2 UNIQUENESS OF FIRE2.1 Introduction Wind and earthquakes can be considered to b Wind and earthquakes can be considered to be “natural” phenomena o e “natural” phenomena o e “natural” phenomena over which designers ver which designers have no control except perhaps to choose the location of buildings more carefully on the basis of historical records and to design building to resist sufficiently high loads or accelerations for the particular location. Dead and live loads in buildings are the result of gravity. All of these loads are variable and it is possible (although generally unlikely) that the loads may exceed the resistance of the critical structural members resulting in structural failure.The nature and influence of fires in buildings are quite different to those associated with other“loads” to which a building may be subjected to. The essential differences are described in the following sections.2.2 Origin of FireIn most situations (ignoring bush fires), fire originates from human activities within the building or the malfunction of equipment placed within the building to provide a serviceable environment. It follows therefore that it is possible to influence the rate of fire starts by influencing human behaviour, limiting and monitoring human behaviour and improving the design of equipment and its maintenance. This is not the case for the usual loads applied to a building.2.3 Ability to InfluenceSince wind and earthquake are directly functions of nature, it is not possible to influence such events to any extent. One has to anticipate them and design accordingly. It may be possibleto influence the level of live load in a building by conducting audits and placing restrictions on contents. However, in the case of a fire start, there are many factors that can be brought to bear to influence the ultimate size of the fire and its effect within the building. It is known that occupants within a building will often detect a fire and deal with it before it reaches a sig- nificant size. It is estimated that less than one fire in five (Favre, 1996) results in a call to the fire brigade and for fires reported to the fire brigade, the majority will be limited to the room of fire origin. Inoc- cupied spaces, olfactory cues (smell) provide powerful evidence of the presence of even a small fire. The addition of a functional smoke detection system will further improve the likelihood of detection and of action being taken by the occupants.Fire fighting equipment, such as extinguishers and hose reels, is generally provided within buildings for the use of occupants and many organisations provide training for staff in respect ofthe use of such equipment.The growth of a fire can also be limited by automatic extinguishing systems such as sprinklers, which can be designed to have high levels of effectiveness.Fires can also be limited by the fire brigade depending on the size and location of the fire at the time of arrival.2.4 Effects of FireThe structural elements in the vicinity of the fire will experience the effects of heat. The temperatures within the structural elements will increase with time of exposure to the fire, the rate of temperature rise being dictated by the thermal resistance of the structural element and the severity of the fire. The increase in temperatures within a member will result in both thermal expansion and,eventually,a reduction in the structural resistance of the member. Differential thermal expansion will lead to bowing of a member. Significant axial expansion willbe accommodated in steel members by either overall or local buckling or yielding of local- ised regions. These effects will be detrimental for columns but for beams forming part of a floorsystem may assist in the development of other load resisting mechanisms (see Section 4.3.5).With the exception of the development of forces due to restraint of thermal expansion, fire does not impose loads on the structure but rather reduces stiffness and strength. Such effects are not instantaneous but are a function of time and this is different to the effects of loads such as earthquake and wind that are more or less instantaneous.Heating effects associated with a fire will not be significant or the rate of loss of capacity will be slowed if:(a) the fire is extinguished (e.g. an effective sprinkler system)(b) the fire is of insufficient severity –– insufficient fuel, and/or(b) the fire is of insufficient severity(c)the structural elements have sufficient thermal mass and/or insulation to slow the rise in internal temperatureFire protection measures such as providing sufficient axis distance and dimensions for concrete elements, and sufficient insulation thickness for steel elements are examples of (c). These are illustrated in Figure 2.The two situations described in the introduction are now considered.3 FIRE WITHIN BUILDINGS3.1 Fire Safety ConsiderationsThe implications of fire within the occupied parts of the office building (Figure 1) (Situation 2) are now considered. Fire statistics for office buildings show that about one fatality is expected in an office building for every 1000 fires reported to the fire brigade. This is an orderof magnitude less than the fatality rate associated with apartment buildings. More than two thirdsof fires occur during occupied hours and this is due to the greater human activity and the greater use of services within the building. It is twice as likely that a fire that commences out of normal working hours will extend beyond the enclosure of fire origin.A relatively small fire can generate large quantities of smoke within the floor of fire origin.If the floor is of open-plan construction with few partitions, the presence of a fire during normal occupied hours is almost certain to be detected through the observation of smoke on the floor. The presence of full height partitions across the floor will slow the spread of smoke and possibly also the speed at which the occupants detect the fire. Any measures aimed at improving housekeeping, fire awareness and fire response will be beneficial in reducing the likelihood of major fires during occupied hours.For multi-storey buildings, smoke detection systems and alarms are often provided to give “automatic” detection and warning to the occupants. An alarm signal is also transm itted to the fire brigade.Should the fire not be able to be controlled by the occupants on the fire floor, they will need to leave the floor of fire origin via the stairs. Stair enclosures may be designed to be fire-resistant but this may not be sufficient to keep the smoke out of the stairs. Many buildings incorporate stair pressurisation systems whereby positive airflow is introduced into the stairs upon detection of smoke within the building. However, this increases the forces required to open the stair doors and makes it increasingly difficult to access the stairs. It is quite likely that excessive door opening forces will exist(Fazio et al,2006)From a fire perspective, it is common to consider that a building consists of enclosures formed by the presence of walls and floors.An enclosure that has sufficiently fire-resistant boundaries (i.e. walls and floors) is considered to constitute a fire compartment and to be capableof limiting the spread of fire to an adjacent compartment. However, the ability of such boundariesto restrict the spread of fire can be severely limited by the need to provide natural lighting (windows)and access openings between the adjacent compartments (doors and stairs). Fire spread via the external openings (windows) is a distinct possibility given a fully developed fire. Limit- ing the window sizes and geometry can reduce but not eliminate the possibility of vertical fire spread.By far the most effective measure in limiting fire spread, other than the presence of occupants, is an effective sprinkler system that delivers water to a growing fire rapidly reducing the heat being generated and virtually extinguishing it.3.2 Estimating Fire SeverityIn the absence of measures to extinguish developing fires, or should such systems fail; severe fires can develop within buildings.In fire engineering literature, the term “fire load” refers to the quantity of combustibles within an enclosure and not the loads (forces) applied to the structure during a fire. Similarly, fire load density refers to the quantity of fuel per unit area. It is normally expressed in terms of MJ/m2or kg/m 2of wood equivalent. Surveys of combustibles for various occupancies (i.e offices, retail,hospitals, warehouses, etc)have been undertaken and a good summary of the available data is given in FCRC (1999). As would be expected, the fire load density is highly variable. Publications such as the International Fire Engineering Guidelines (2005) give fire load data in terms of the mean and 80th percentile.The latter level of fire load density is sometimes taken asthe characteristic fire load density and is sometimes taken as being distributed according to a Gumbel distribution (Schleich et al, 1999).The rate at which heat is released within an enclosure is termed the heat release rate (HRR) and normally expressed in megawatts (MW). The application of sufficient heat to a combustible material results in the generation of gases some of which are combustible. This process is called pyrolisation.Upon coming into contact with sufficient oxygen these gases ignite generating heat. The rate of burning(and therefore of heat generation) is therefore dependent on the flow of air to the gases generated by the pyrolising fuel.This flow is influenced by the shape of the enclosure (aspect ratio), and the position and size of any potential openings. It is found from experiments with single openings in approximately cubic enclosures that the rate of burning is directly proportional to A h where A is the area of the opening and h is the opening height. It is known that for deep enclosures with single openings that burning will occur initially closest to the opening moving back into the enclosure once the fuel closest to the opening is consumed (Thomas et al, 2005). Significant temperature variations throughout such enclosures can be expected.The use of the word ‘opening’ in relation to real building enclosures refers to any openings present around the walls including doors that are left open and any windows containing non fire-resistant glass.It is presumed that such glass breaks in the event of development of a significant fire. If the windows could be prevented from breaking and other sources of air to the enclosure limited, then the fire would be prevented from becoming a severe fire.V arious methods have been developed for determining the potential severity of a fire within an enclosure.These are described in SFPE (2004). The predictions of these methods are variable and are mostly based on estimating a representative heat release rate (HRR) and the proportion of total fuel ς likely to be consumed during the primary burning stage (Figure 4). Further studies of enclosure fires are required to assist with the development of improved models,as the behaviour is very complex.3.3 Role of the Building StructureIf the design objectives are to provide an adequate level of safety for the occupants and protection of adjacent properties from damage, then the structural adequacy of the building in fire need only be sufficient to allow the occupants to exit the building and for the building to ultimately deform in a way that does not lead to damage or fire spread to a building located on an adjacent site.These objectives are those associated with most building regulations including the Building Code of Australia (BCA). There could be other objectives including protection of the building against significant damage. In considering these various objectives, the following should be taken into account when considering the fire resistance of the building structure.3.3.1 Non-Structural ConsequencesSince fire can produce smoke and flame, it is important to ask whether these outcomes will threaten life safety within other parts of the building before the building is compromised by a lossof structural adequacy? Is search and rescue by the fire brigade not feasible given the likely extent of smoke? Will the loss of use of the building due to a severe fire result in major property and income loss? If the answer to these questions is in the affirmative, then it may be necessary to minimise the occurrence of a significant fire rather than simply assuming that the building structure needs to be designed for high levels of fire resistance. A low-rise shopping centre with levels interconnected by large voids is an example of such a situation.3.3.2 Other Fire Safety SystemsThe presence of other systems (e.g. sprinklers) within the building to minimise the occurrence of a serious fire can greatly reduce the need for the structural elements to have high levels of fire resistance. In this regard, the uncertainties of all fire-safety systems need to be considered. Irrespective of whether the fire safety system is the sprinkler system, stair pressurisation, compartmentation or the system giving the structure a fire-resistance level (e.g. concrete cover), there is an uncertainty of performance. Uncertainty data is available for sprinkler systems(because it is relatively easy to collect) but is not readily available for the other fire safety systems. This sometimes results in the designers and building regulators considering that only sprinkler systems are subject to uncertainty. In reality, it would appear that sprinklers systems have a high level of performance and can be designed to have very high levels of reliability.3.3.3 Height of BuildingIt takes longer for a tall building to be evacuated than a short building and therefore the structure of a tall building may need to have a higher level of fire resistance. The implications of collapse of tall buildings on adjacent properties are also greater than for buildings of only several storeys.3.3.4 Limited Extent of BurningIf the likely extent of burning is small in comparison with the plan area of the building, then the fire cannot have a significant impact on the overall stability of the building structure. Examples of situations where this is the case are open-deck carparks and very large area building such as shopping complexes where the fire-effected part is likely to be small in relation to area of the building floor plan.3.3.5 Behaviour of Floor ElementsThe effect of real fires on composite and concrete floors continues to be a subject of much research.Experimental testing at Cardington demonstrated that when parts of a composite floor are subject to heating, large displacement behaviour can develop that greatly assists the load carrying capacity of the floor beyond that which would predicted by considering only the behaviour of the beams and slabs in isolation.These situations have been analysed by both yield line methods that take into account the effects of membrane forces (Bailey, 2004) and finite element techniques. In essence, the methods illustrate that it is not necessary to insulate all structural steel elements in a composite floor to achieve high levels of fire resistance.This work also demonstrated that exposure of a composite floor having unprotected steel beams, to a localised fire, will not result in failure of the floor.A similar real fire test on a multistory reinforced concrete building demonstrated that the real structural behaviour in fire was significantly different to that expected using small displacement theory as for normal tempera- ture design (Bailey, 2002) with the performance being superior than that predicted by considering isolated member behaviour.3.4 Prescriptive Approach to DesignThe building regulations of most countries provide prescriptive requirements for the design of buildings for fire.These requirements are generally not subject to interpretation and compliance with them makes for simpler design approvalapproval––although not necessarily the most cost-effective designs.These provisions are often termed deemed-to-satisfy (DTS) provisions. Allcovered––the provision of emergency exits, aspects of designing buildings for fire safety are coveredspacings between buildings, occupant fire fighting measures, detection and alarms, measures for automatic fire suppression, air and smoke handling requirements and last, but not least, requirements for compartmentation and fire resistance levels for structural members. However, there is little evidence that the requirements have been developed from a systematic evaluation of fire safety. Rather it would appear that many of the requirements have been added one to anotherto deal with another fire incident or to incorporate a new form of technology. There does not appear to have been any real attempt to determine which provision have the most significant influence on fire safety and whether some of the former provisions could be modified.The FRL requirements specified in the DTS provisions are traditionally considered to result in member resistances that will only rarely experience failure in the event of a fire.This is why it is acceptable to use the above arbitrary point in time load combination for assessing members in fire. There have been attempts to evaluate the various deemed-to-satisfy provisions (particularly the fire- resistance requirements)from a fire-engineering perspective taking into account the possible variations in enclosure geometry, opening sizes and fire load (see FCRC, 1999).One of the outcomes of this evaluation was the recognition that deemed-to- satisfy provisions necessarily cover the broad range of buildings and thus must, on average, be quite onerous because of the magnitude of the above variations.It should be noted that the DTS provisions assume that compartmentation works and that fire is limited to a single compartment. This means that fire is normally only considered to exist at one level. Thus floors are assumed to be heated from below and columns only over one storey height.3.5 Performance-Based DesignAn approach that offers substantial benefits for individual buildings is the move towards performance-based regulations. This is permitted by regulations such as the BCA which state thata designer must demonstrate that the particular building will achieve the relevant performance requirements. The prescriptive provisions (i.e. the DTS provisions) are presumed to achieve these requirements. It is necessary to show that any building that does not conform to the DTS provisions will achieve the performance requirements.But what are the performance requirements? Most often the specified performance is simplya set of performance statements (such as with the Building Code of Australia)with no quantitative level given. Therefore, although these statements remind the designer of the key elements of design, they do not, in themselves, provide any measure against which to determine whether the design is adequately safe.Possible acceptance criteria are now considered.3.5.1 Acceptance CriteriaSome guidance as to the basis for acceptable designs is given in regulations such as the BCA. These and other possible bases are now considered in principle.(i)compare the levels of safety (with respect to achieving each of the design objectives) of the proposed alternative solution with those asso- ciated with a corresponding DTS solution for the building.This comparison may be done on either a qualitative or qualitative risk basis or perhaps a combination. In this case, the basis for comparison is an acceptable DTS solution. Such an approach requires a “holistic” approach to safety whereby all aspects relevant to safety, including the structure, are considered. This is, by far, the most common basis for acceptance.(ii)undertake a probabilistic risk assessment and show that the risk associated with the proposed design is less than that associated with common societal activities such as using pub lic transport. Undertaking a full probabilistic risk assessment can be very difficult for all but the simplest situations.Assuming that such an assessment is undertaken it will be necessary for the stakeholders to accept the nominated level of acceptable risk. Again, this requires a “holistic” approach to fire safety.(iii) a design is presented where it is demonstrated that all reasonable measures have been adopted to manage the risks and that any possible measures that have not been adopted will have negligible effect on the risk of not achieving the design objectives.(iv) as far as the building structure is concerned,benchmark the acceptable probability of failure in fire against that for normal temperature design. This is similar to the approach used when considering Building Situation 1 but only considers the building structure and not the effects of flame or smoke spread. It is not a holistic approach to fire safety.Finally, the questions of arson and terrorism must be considered. Deliberate acts of fire initiation range from relatively minor incidents to acts of mass destruction.Acts of arson are well within the accepted range of fire events experienced by build- ings(e.g. 8% of fire starts in offices are deemed "suspicious"). The simplest act is to use a small heat source to start a fire. The resulting fire will develop slowly in one location within the building and will most probably be controlled by the various fire- safety systems within the building. The outcome is likely to be the same even if an accelerant is used to assist fire spread.An important illustration of this occurred during the race riots in Los Angeles in 1992 (Hart 1992) when fires were started in many buildings often at multiple locations. In the case of buildings with sprinkler systems,the damage was limited and the fires significantly controlled.Although the intent was to destroy the buildings,the fire-safety systems were able to limit the resulting fires. Security measures are provided with systems such as sprinkler systems and include:- locking of valves- anti-tamper monitoring- location of valves in secure locationsFurthermore, access to significant buildings is often restricted by security measures.The very fact that the above steps have been taken demonstrates that acts of destruction within buildings are considered although most acts of arson do not involve any attempt to disable the fire-safety systems.At the one end of the spectrum is "simple" arson and at the other end, extremely rare acts where attempts are made to destroy the fire-safety systems along with substantial parts of thebuilding.This can be only achieved through massive impact or the use of explosives. The latter may be achieved through explosives being introduced into the building or from outside by missile attack.The former could result from missile attack or from the collision of a large aircraft. The greater the destructiveness of the act,the greater the means and knowledge required. Conversely, the more extreme the act, the less confidence there can be in designing against such an act. This is because the more extreme the event, the harder it is to predict precisely and the less understood will be its effects. The important point to recognise is that if sufficient means can be assembled, then it will always be possible to overcome a particular building design.Thus these acts are completely different to the other loadings to which a building is subjected such as wind,earthquake and gravity loading. This is because such acts of destruction are the work of intelligent beings and take into account the characteristics of the target.Should high-rise buildings be designed for given terrorist activities,then terrorists will simply use greater means to achieve the end result.For example, if buildings were designed to resist the impact effects from a certain size aircraft, then the use of a larger aircraft or more than one aircraft could still achieve destruction of the building. An appropriate strategy is therefore to minimise the likelihood of means of mass destruction getting into the hands of persons intent on such acts. This is not an engineering solution associated with the building structure.It should not be assumed that structural solutions are always the most appropriate, or indeed, possible.In the same way, aircrafts are not designed to survive a major fire or a crash landing but steps are taken to minimise the likelihood of either occurrence.The mobilization of large quantities of fire load (the normal combustibles on the floors) simultaneously on numerous levels throughout a building is well outside fire situations envisaged by current fire test standards and prescriptive regulations. Risk management measures to avoid such a possibility must be considered.4 CONCLUSIONSificantly from other “loads” such as wind, live load and earthquakes in significantlyFire differs signrespect of its origin and its effects.Due to the fact that fire originates from human activities or equipment installed within buildings, it is possible to directly influence the potential effects on the building by reducing the rate of fire starts and providing measures to directly limit fire severity.The design of buildings for fire safety is mostly achieved by following the prescriptive requirements of building codes such as the BCA. For situations that fall outside of the scope of such regulations, or where proposed designs are not in accordance with the prescriptive requirements, it is possible to undertake performance-based fire engineering designs.However,。
室内装饰装修设计外文文献翻译中英文
外文文献翻译(含:英文原文及中文译文)文献出处:Y Miyazaki. A Brief Description of Interior Decoration [J]. Building & Environment, 2005, 40(10):41-45.英文原文A Brief Description of Interior DecorationY Miyazaki一、An interior design element1 Spatial elementsThe rationalization of space and giving people a sense of beauty is the basic task of design. We must dare to explore the new image of the times and technologies that are endowed with space. We should not stick to the spatial image formed in the past.2 color requirementsIn addition to affecting the visual environment, indoor colors also directly affect people's emotions and psychology. Scientific use of color is good for work and helps health. The proper color processing can meet the functional requirements and achieve the beauty effect. In addition to observing the general laws of color, interior colors also vary with the aesthetics of the times.3 light requirementsHumans love the beauty of nature and often direct sunlight into theinterior to eliminate the sense of darkness and closure in the interior, especially the top light and the soft diffuse light, making the interior space more intimate and natural. The transformation of light and shadow makes the interior richer and more colorful, giving people a variety of feelings.4 decorative elementsThe indispensable building components such as columns, walls, and the like in the entire indoor space are combined with the function and need to be decorated to jointly create a perfect indoor environment. By making full use of the texture characteristics of different decorative materials, you can achieve a variety of interior art effects with different styles, while also reflecting the historical and cultural characteristics of the region.5 furnishingsIndoor furniture, carpets, curtains, etc., are all necessities of life. Their shapes are often furnished and most of them play a decorative role. Practicality and decoration should be coordinated with each other, and the functions and forms of seeking are unified and changed so that the interior space is comfortable and full of personality.6 green elementsGreening in interior design is an important means to improve the indoor environment. Indoor flowering trees are planted, and the use ofgreenery and small items to play a role in diffusing indoor and outdoor environments, expanding the sense of interior space, and beautifying spaces all play an active role.二、The basic principles of interior design1 interior decoration design to meet the functional requirementsThe interior design is based on the purpose of creating a good indoor space environment, so as to rationalize, comfort, and scientize the indoor environment. It is necessary to take into account the laws of people's activities to handle spatial relationships, spatial dimensions, and spatial proportions; to rationally configure furnishings and furniture, and to properly resolve indoor environments. V entilation, lighting and lighting, pay attention to the overall effect of indoor tone.2 interior design to meet the spiritual requirementsThe spirit of interior design is to influence people's emotions and even influence people's will and actions. Therefore, we must study the characteristics and laws of people's understanding; study the emotions and will of people; and study the interaction between people and the environment. Designers must use various theories and methods to impact people's emotions and sublimate them to achieve the desired design effect. If the indoor environment can highlight a certain concept and artistic conception, then it will have a strong artistic appeal and better play its role in spiritual function.3 Interior design to meet modern technical requirementsThe innovation of architectural space is closely related to the innovation of structural modeling. The two should be harmonized and unified, fully considering the image of the structural Sino-U.S. and integrating art and technology. This requires that interior designers must possess the necessary knowledge of the type of structure and be familiar with and master the performance and characteristics of the structural system. Modern interior design is in the category of modern science and technology. To make interior design better meet the requirements of spiritual function, we must maximize the use of the latest achievements in modern science and technology.4 Interior design must meet the regional characteristics and national style requirementsDue to differences in the regions where people live, geographical and climatic conditions, the living habits of different ethnic groups are not the same as cultural traditions, and there are indeed great differences in architectural styles. China is a multi-ethnic country. The differences in the regional characteristics, national character, customs, and cultural literacy of various ethnic groups make indoor decoration design different. Different styles and features are required in the design. We must embody national and regional characteristics to evoke people’s national self-respect and self-confidence.三、Points of interior designThe interior space is defined by the enclosure of the floor, wall, and top surface, thus determining the size and shape of the interior space. The purpose of interior decoration is to create a suitable and beautiful indoor environment. The floor and walls of the interior space are the backdrop for people and furnishings and furnishings, while the differences on the top surface make the interior space more varied.1 Base decoration ----- Floor decorationThe basic surface ----- is very important in people's sights. The ground floor is in contact with people, and the line of sight is near, and it is in a dynamic change. It is one of the important factors of interior decoration. Meet the following principles:2 The base should be coordinated with the overall environment to complement each other and set off the atmosphereFrom the point of view of the overall environmental effect of space, the base should be coordinated with the ceiling and wall decoration. At the same time, it should play a role in setting off the interior furniture and furnishings.3 Pay attention to the division, color and texture of the ground patternGround pattern design can be roughly divided into three situations: The first is to emphasize the independent integrity of the pattern itself,such as meeting rooms, using cohesive patterns to show the importance of the meeting. The color should be coordinated with the meeting space to achieve a quiet, focused effect; the second is to emphasize the pattern of continuity and rhythm, with a certain degree of guidance and regularity, and more for the hall, aisle and common space; third It emphasizes the abstractness of the pattern, freedom, and freedom, and is often used in irregular or layout-free spaces.4 Meeting the needs of the ground structure, construction and physical properties of the buildingWhen decorating the base, attention should be paid to the structure of the ground floor. In the premise of ensuring safety, it is convenient for construction and construction. It cannot be a one-sided pursuit of pattern effects, and physical properties such as moisture-proof, waterproof, thermal insulation, and thermal insulation should be considered. need. The bases are available in a wide variety of types, such as: wooden floors, block floors, terrazzo floors, plastic floors, concrete floors, etc., with a wide variety of patterns and rich colors. The design must be consistent with the entire space environment. Complementary to achieve good results.四、wall decorationIn the scope of indoor vision, the vertical line of sight between the wall and the person is in the most obvious position. At the same time, thewall is the part that people often contact. Therefore, the decoration of the wall is very important for the interior design. The following design principles must be met: 1 IntegrityWhen decorating a wall, it is necessary to fully consider the unity with other parts of the room, and to make the wall and the entire space a unified whole.2 PhysicalThe wall surface has a larger area in the interior space, and the status is more important and the requirements are higher. The requirements for sound insulation, warmth protection, fire prevention, etc. in the interior space vary depending on the nature of the space used, such as the guest room, high requirements. Some, while the average unit canteen, requiresa lower number.3 ArtistryIn the interior space, the decorative effect of the wall plays an important role in rendering and beautifying the indoor environment. The shape of the wall, the partition pattern, the texture and the interior atmosphere are closely related to each other. In order to create the artistic effect of the interior space, the wall The artistry of the surface itself cannot be ignored.The selection of wall decoration styles is determined according to the above principles. The forms are roughly the following: plasteringdecoration, veneering decoration, brushing decoration, coil decoration. Focusing on the coil decoration here, with the development of industry, there are more and more coils that can be used to decorate walls, such as: plastic wallpaper, wall cloth, fiberglass cloth, artificial leather, and leather. These materials are characterized by the use of It is widely used, flexible and free, with a wide variety of colors, good texture, convenient construction, moderate prices, and rich decorative effects. It is a material that is widely used in interior design.五、Ceiling decorationThe ceiling is an important part of the interior decoration, and it is also the most varied and attractive interface in the interior space decoration. It has a strong sense of perspective. Through different treatments, the styling of lamps and lanterns can enhance the space appeal and make the top surface rich in shape. Colorful, novel and beautiful.1 Design principlesPay attention to the overall environmental effects.The ceiling, wall surface and base surface together make up the interior space and jointly create the effects of the indoor environment. The design should pay attention to the harmonization of the three, and each has its own characteristics on a unified basis.The top decoration should meet the applicable aesthetic requirements.In general, the effect of indoor space should be lighter and lighter. Therefore, it is important to pay attention to the simple decoration of the top decoration, highlight the key points, and at the same time, have a sense of lightness and art.The top decoration should ensure the rationality and safety of the top structure. Cannot simply pursue styling and ignore safety2 top design(1) Flat roofThe roof is simple in construction, simple in appearance, and convenient in decoration. It is suitable for classrooms, offices, exhibition halls, etc. Its artistic appeal comes from the top shape, texture, patterns, and the organic configuration of the lamps.(2) Convex ceilingThis kind of roof is beautiful and colorful, with a strong sense of three-dimensionality. It is suitable for ballrooms, restaurants, foyers, etc. It is necessary to pay attention to the relationship between the primary and secondary relationships and the height difference of various concavo-convex layers. It is not appropriate to change too much and emphasize the rhythm of rhythm and the artistry of the overall space. .(3) Suspended ceilingV arious flaps, flat plates or other types of ceilings are hung under the roof load-bearing structures. These ceilings are often used to meetacoustic or lighting requirements or to pursue certain decorative effects. They are often used in stadiums, cinemas, and so on. In recent years, this type of roof has also been commonly used in restaurants, cafes, shops, and other buildings to create special aesthetics and interests.(4) Well format ceilingIt is in the form of a combined structural beam, in which the main and secondary beams are staggered and the relationship between the wells and beams, together with a ceiling of lamps and gypsum floral designs, is simple and generous, with a strong sense of rhythm.(5) Glass ceilingThe halls and middle halls of modern large-scale public buildings are commonly used in this form, mainly addressing the needs of large-scale lighting and indoor greening, making the indoor environment richer in natural appeal, and adding vitality to large spaces. It is generally in the form of a dome, a cone, and a zigzag. In short, interior decoration design is a comprehensive discipline, involving many disciplines such as sociology, psychology, and environmental science, and there are many things that we need to explore and study. This article mainly elaborated the basic principles and design methods of interior decoration design. No matter what style belongs to the interior design door, this article gives everyone a more in-depth understanding and comprehension of interior design. If there are inadequacies, let the criticism correct me.中文译文室内装饰简述Y Miyazaki一室内装饰设计要素1 空间要素空间的合理化并给人们以美的感受是设计基本的任务。
外文翻译及中文译文
车床用于车外圆、端面和镗孔等加工的机床称作车床。
车削很少在其他种类的机床上进行,因为其他机床都不能像车床那样方便地进行车削加工。
由于车床除了用于车外圆还能用于镗孔、车端面、钻孔和铰孔,车床的多功能性可以使工件在一次定位安装中完成多种加工。
这就是在生产中普遍使用各种车床比其他种类的机床都要多的原因。
两千多年前就已经有了车床。
现代车床可以追溯到大约1797年,那时亨利•莫德斯利发明了一种具有把主轴和丝杆的车床。
这种车床可以控制工具的机械进给。
这位聪明的英国人还发明了一种把主轴和丝杆相连接的变速装置,这样就可以切削螺纹。
车床的主要部件:床身、主轴箱组件、尾架组件、拖板组、变速齿轮箱、丝杆和光杆。
床身是车床的基础件。
它通常是由经过充分正火或时效处理的灰铸铁或者球墨铸铁制成,它是一个坚固的刚性框架,所有其他主要部件都安装在床身上。
通常在球墨铸铁制成,它是一个坚固的刚性框架,所有其他主要部件都安装在床身上。
通常在床身上面有内外两组平行的导轨。
一些制造厂生产的四个导轨都采用倒“V”,而另一些制造厂则将倒“V”形导轨和平面导轨结合。
由于其他的部件要安装在导轨上并(或)在导轨上移动,导轨要经过精密加工,以保证其装配精度。
同样地,在操作中应该小心,以避免损伤导轨。
导轨上的任何误差,常常会使整个机床的精度遭到破坏。
大多数现代车床的导轨要进行表面淬火处理。
以减少磨损和擦伤,具有更大的耐磨性。
主轴箱安装在床身一端内导轨的固定位置上。
它提供动力。
使工件在各种速度下旋转。
它基本上由一个安装在精密轴承中的空心轴和一系列变速齿轮---类似于卡车变速箱所组成,通过变速齿轮,主轴可以在许多中转速的旋转。
大多数车床有8~18中转速,一般按等比级数排列。
在现代车床上只需扳动2~4个手柄,就能得到全部挡位的转速。
目前发展的趋势是通过电气的或机械的装置进行无级变速。
由于车床的精度在很大程度上取决于主轴,因此主轴的结构尺寸较大,通常安装在紧密配合的重型圆锤滚子轴承或球轴承中。
