建筑方面的英文文献.1doc_secret
本科毕业论文
外文文献及译文
文献、资料题目：SYSTEMS INTEGRATION 文献、资料来源：International Journal
文献、资料发表（出版）日期：2005.5.30院（部）：城市建设学院
专业：建筑环境与设备工程专业
班级：4
姓名：XXX
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中文译文：
动应力下304L不锈钢振动时效的成效评估
摘要
振动时效是一种程序，通过动应力振动的方式来减少残余应力。目前，定时和定量考核振动时效的成效问题十分重要，荷载或动应力在振动时效期间对焊接结构减少残余应力有直接影响。本文论述了304L不锈钢振动时效期间焊接试样的循环应力应变及儒变机制。根据实验结果，提出了残余应力对动应力松弛的数学模型，此模型用于评价制造HT—7U Tokamak焊接结构振动时效的影响。残余应力测量值与计算值之间的差额约为11%，结果表明，采用动态应力振动时效效果评价是实用的。
关键词：振动时效；残余应力；荷载；动态应力；焊接
1 引言
振动时效表示动应力下残余应力的减少量，虽然已广泛应用了40多年的振动时效机理仍在调查中，但振动时效的定量考核依然是一个十分重要的问题。一般来说，振动时效处理机附属于要求应力松弛结构的偏心大电机，相结合的动态应力和残余应力可超过材料的屈服强度，从而引发局部塑性变形和应力松弛。
残余应力的减少影响了振动块的自然特性，振动时效效果往往根据比较前后振动时效振动响应曲线[2]来评估，例如移频共振[3]。但这种方法的有效性，虽然于振动时效后很快步入但却只是定性评价。
定量评价结果可以通过测量振动时效前后同一点处的残余应力得出。可采用钻孔和XRD两种方法测量焊接残余应力但复杂而费时，由于两种测量方法必需同时采用，故这种评估方法并不常用。
焊接结构振动时效期间评价残余应力的减少需要一种简单而且定性的方法。残余应力是没有外部载荷情况下自我平衡的内应力。焊接结构振动时效期间，循环应力或动态应力对结构减少残余应力有直接影响。局部残余应力是循环叠加应力的平均应力。在振动时效期间动态应力振幅可使用应变计很容易的测量出来。本文论述了动态应力疲劳和残余应力减少的定量关系。此项研究的主要目的是要为314L不锈钢再循环载荷下的焊接应力松弛建立一个模型。因此，又找到了一个能定量而简洁的评估振动时效的方法，该模型适用于HT—7U Tokamak焊接结构的振动时效。
2 不锈钢的循环应力应变
Electro-hydraulic servo系统疲劳实验机（MTS810）可促进振动时效期间可模拟动态负荷应力的振动循环。板型材料为304L不锈钢，其组成成分为（wt%）Fe-0.02C-1.38Mn-0.47Si-0.03P-0.005S-18.2Cr-8.7Ni-0.05N。加载前试样焊接加热变形会产生残余应力，试样中的单条焊缝有100毫米长，应变传感器就安装在试样的焊缝上（如图1）。张力压缩动态应力（R10）用于模拟振动时效处理，在循环加载期间测量循环应变，如图2（a）表示不同周期焊缝上的循环应力和局部应变。受控负荷周期循环间有恒定的振幅，因而，动态应力振幅是一恒量（±50MPa在图2中）。应变振幅并不是在固定不变的，而平均应变在拉应力方向逐渐增加，此拉应力表明了方向拉伸循环塑性应变或循环儒变。如图2（b）表示不同载荷下的循环应变，图中的每条线代表一个加载周期。在第一个循环第50周期时儒变较高，但其速度减慢。循环儒变在200个周期后逐渐稳定，而在第200和第300个周期之间的差别很小。
图2 304L焊接接头的循环加载和应变
图3表明了另一个焊接试样在不同加载周期下的循环应变，载荷应力振幅为±100MPa，它也表明循环儒变速度减慢，但相比在±50MPa循环应力下循环儒变达到稳定
图1 试样上的应变机
需要更多周期。循环儒变从第200到300个周期仍然增加，并且进一步研究表明，在600个周期之后发生儒变稳定。结果显示动态应力振幅越大循环儒变越明显，较多周期之后会产生儒变稳定。
304L的屈服应力约为320MPa，动应力时效期间的动应力在塑性区域。上述实验结果表明，循环儒变与周期性动态应力和焊接接头残余应力息息相关。通常焊缝径向残余应力（沿焊缝方向）为拉应力，它能达到材料的屈服应力。从观察到的疲劳点来看原因是焊接结构中存在残余应力，此残余应力可认为是张力压缩循环载荷期间的平均应力，但每个周期中的平均应力只有一个方向产生应力高峰，因此，在每个周期中都会有不同于其他方向的塑性流动。尽管动态应力是在弹性变形区内，但由于Bauschiner效应周期性塑性应变仍很高，这种情况下，在每个周期中很小的动态应力就能产生大量的塑性流动产生循环儒变。以上实验证明了不锈钢焊接结构振动时效期间的循环儒变机制。
3 循环儒变与残余应力松弛
许多研究员致力于循环载荷期间的残余应力松弛，Morrow和Sinchair[6]基于轴向疲劳实验中应力松弛的残余应力松弛预测进行了研究。他们针对第一个周期的平均应力、循环次数、材料屈服强度和动应力振幅提出了一个模型。Kodama[7]测量出了碳钢的残余应力减少量，指出残余应力松弛随疲劳循环的对数呈线性变化，其速率正比于应力振幅。Smith.et al[8]用弹塑性有限元模型分析残余应力和动态加载的相互作用，发现残余应力松弛甚至发生在低循环应变范围内。Zhuang和Halford[9]提出了一种有限元模型来估计残余应力松弛，此模型的参数包括残余应力的规模和布局、冷作程度、动应力和平均应力、载荷循环系数。他们的研究结果表明主要的残余应力松弛发生在早期阶段。
图3 304L焊接试样循环应力应变（应力振幅=100MPa）
以上学者的研究表明，参与应力松弛取决于循环载荷主要受以下影响：
（1）残余应力的初始震级和梯度；（2）动应力振幅；（3）循环次数；（4）循环载荷下材料的性质。
4 循环载荷下的焊接残余应力松弛
正如前节所述，残余应力位于焊缝处则屈服强度较大，材料的屈服应力可认为是初始应力。因此，循环载荷下304L不锈钢的焊接应力松弛主要受动应力振幅和循环次数影响。选取图2（b）中每条线的中点，图4中的圆点连线就表示在±500MPa动态应力下焊接的循环儒变曲线。
通过以上的儒变曲线，提出了循环儒变的相应方程，看图4中的实线，
表示N次循环后的总儒变；N表示循环次数；P1和P2是依赖于材料初始残余应力
和循环应力—应变反映的系数常数；50表示动应力振幅为50MPa。为估计残余应力松弛，残余应力减少量表示为
其中E表示动态模量，它与根据图2计算出的载荷有关。基于上述结果和焊接残余应力的概念，304L不锈钢在循环载荷下的残余应力减少量可表示为
(3)
其中为动态应力振幅，K为初始残余应力与材料屈服应力的比值，作为径向焊缝K可取1。
循环次数（N）循环次数（N）
图4 不同周期314L焊接试样的循环儒变图5 304不锈钢动应力下多次载荷循环后焊接应力减少量
5 动态应力评价残余应力松弛
方程（3）给出了一种方法来定量评价动态时效效果，基于方程（3）和图5表示了不同动态应力下残余应力的减少量。
304L焊接残余应力用X射线衍射法进行测量，试样的材料和尺寸与前述相同，图
6表示循环载荷的三种试样，循环应力的测点在焊缝的熔合线上，初始焊接用X 射线衍射法，径向残余应力约为295兆帕，三种动态应力振幅±30MPa 、±60MPa 、±90MPa 分别在三种试样的循环载荷期间选取。
图6焊接式样和残余应力测量点 图7 HT-7Utokamak 结构形状
表格1 残余应力测量值与计算值
动应力振幅 径向应力 测量值 计算值 差额 （MP ） （MP ） （MP ） （MP ） （%） ±30 239 56 58 -3
±60 161 134 117 13
±90 98 197 176 11
表格1表示出了600次循环载荷后的残余应力测量结果和参与应力减少量，基于方程（3）计算出的残余应力减少量也在表格中显示出来。
表中数据表明残余应力的测量值与计算值之间的误差不超过15%，并对HT-7UTokamak 焊接结构振动时效期间进行了进一步研究。
6 动应力振动时效评价
图7为HT-7UTokamak 结构的底板，其材料为304L 不锈钢，由5块304L 薄板焊接而成，板直径为7.6米，厚70毫米，总重量超过34吨。板料要在焊接加工后进行振动时效处理，使用橡胶粘成均匀的圆板，而在振动时效期间的励磁固定在中央孔洞的边缘，该板加工共振频率为47.83HZ 和60.68HZ ，振动时效总时间约15分钟。
对于厚大焊接结构，X 射线衍射法和钻孔法都可用来测量表面应力，X 射线测量深度为几厘米，钻孔法测量深度为几毫米（仅3毫米的洞，可用于盲人文件）。
测量点
振动时效前后对焊接板料的残余应力测量就采用此法，测量点的位置如图8，振动时效处理后径向残余应力的平均减少量为39.5MPa 。
图8 残余应力测量点的位置 图9 一点的动应变波形
以上六点的动态应力也在振动时效期间用应变计测量，图9表明示波器上一点的动应变曲线（电压信号），并且此点的动应力振幅可测量出来，这六点的动应力振幅是18MPa 。根据方程(3)可计算残余应力的平均跌幅为35MPa ，模型计算和实测结果差额约为11%。
上述结果表明，采用动态应力评价振动时效，一旦测出焊缝上的平均动态应力振幅，振动时效处理后残余应力跌幅的定量结果就能很快得到。
7 结论
用动应力振幅和多次循环能够评价振动时效结果，建立了循环载荷下304L 的残余应力跌幅模型，用此模型估计的残余应力值与实测值吻合。此模型用于评价HT-7UTokamak 焊接结构人工处理期间振动时效的影响，也可计算出残余应力跌幅的计算值与实测值之间的差额约为11%。
2007-4-21
参考文献
[1] Saunders GG, Claxton RA. VSR – a current state-of-the-art appraisal.Residual stress in welded construction and their effects. London: The welding institute; 1978. p. 83–173.
[2] Yang Xu, Mao Cai Sun, Qing Ben Li. Effectiveness criterion for the in situ evaluation of vibratory stress relieving process. Transaction of China welding institution (Chinese) 2002;23(2): 3–73.
[3] James MN, Paterson AE, Sutcliffe N. Constant and variable amplitude loading of6261 aluminum alloy I-beams with welded cover plates –influence of weld quality and stress relief. Int J Fatigue 1997;19(2):125–133.
[4] Gourd LM. Principles of welding technology. London: Edward Arnold Ltd.; 1980:80.
[5] Sandor BI. Fundamentals of cyclic stress and strain. Wisconsin: The University of Wisconsin press; 1972:55-59.
[6] Morrow, JoDean, Sinclair GM. Cycle-dependent stress relaxation. ASTM STP 237. American Society for Testing and Materials; 1958:33-40.
[7] Kodama J. The behavior of the residual stress during fatigue stress cycles. In : Proceedings of the international conference on mechanical behavior of materials, Kyoto; 1971. p. 111–118.
[8] Smith DJ, Farrahi GH, Zhu WX, McMahon CA. Experimental measurement and finite element simulation of the interaction between residual stress and mechanical loading. Int Fatigue 2001;23:293–302.
[9] Zhang Wyman Z, Halford Gary R. Investigation of residual stress relaxation under cyclic load. Int J Fatigue 2001;23:S31–37.
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平面设计中英文对照外文翻译文献
(文档含英文原文和中文翻译) 中英文翻译 平面设计 任何时期平面设计可以参照一些艺术和专业学科侧重于视觉传达和介绍。采用多种方式相结合，创造和符号，图像和语句创建一个代表性的想法和信息。平面设计师可以使用印刷，视觉艺术和排版技术产生的最终结果。平面设计常常提到的进程，其中沟通是创造和产品设计。 共同使用的平面设计包括杂志，广告，产品包装和网页设计。例如，可能包括产品包装的标志或其他艺术作品，举办文字和纯粹的设计元素，如形状和颜色统一件。组成的一个最重要的特点，尤其是平面设计在使用前现有材料或不同的元素。 平面设计涵盖了人类历史上诸多领域，在此漫长的历史和在相对最近爆炸视觉传达中的第20和21世纪，人们有时是模糊的区别和重叠的广告艺术，平面设计和美术。毕竟，他们有着许多相同的内容，理论，原则，做法和语言，有时同样的客人或客户。广告艺术的最终目标是出售的商品和服务。在平面
设计，“其实质是使以信息，形成以思想，言论和感觉的经验”。 在唐朝（ 618-906 ）之间的第4和第7世纪的木块被切断打印纺织品和后重现佛典。阿藏印在868是已知最早的印刷书籍。 在19世纪后期欧洲，尤其是在英国，平面设计开始以独立的运动从美术中分离出来。蒙德里安称为父亲的图形设计。他是一个很好的艺术家，但是他在现代广告中利用现代电网系统在广告、印刷和网络布局网格。 于1849年，在大不列颠亨利科尔成为的主要力量之一在设计教育界，该国政府通告设计在杂志设计和制造的重要性。他组织了大型的展览作为庆祝现代工业技术和维多利亚式的设计。 从1892年至1896年威廉?莫里斯凯尔姆斯科特出版社出版的书籍的一些最重要的平面设计产品和工艺美术运动，并提出了一个非常赚钱的商机就是出版伟大文本论的图书并以高价出售给富人。莫里斯证明了市场的存在使平面设计在他们自己拥有的权利，并帮助开拓者从生产和美术分离设计。这历史相对论是，然而，重要的，因为它为第一次重大的反应对于十九世纪的陈旧的平面设计。莫里斯的工作，以及与其他私营新闻运动，直接影响新艺术风格和间接负责20世纪初非专业性平面设计的事态发展。 谁创造了最初的“平面设计”似乎存在争议。这被归因于英国的设计师和大学教授Richard Guyatt，但另一消息来源于20世纪初美国图书设计师William Addison Dwiggins。 伦敦地铁的标志设计是爱德华约翰斯顿于1916年设计的一个经典的现代而且使用了系统字体设计。 在20世纪20年代，苏联的建构主义应用于“智能生产”在不同领域的生产。个性化的运动艺术在俄罗斯大革命是没有价值的，从而走向以创造物体的功利为目的。他们设计的建筑、剧院集、海报、面料、服装、家具、徽标、菜单等。 Jan Tschichold 在他的1928年书中编纂了新的现代印刷原则，他后来否认他在这本书的法西斯主义哲学主张，但它仍然是非常有影响力。 Tschichold ，包豪斯印刷专家如赫伯特拜耳和拉斯洛莫霍伊一纳吉，和El Lissitzky 是平面设计之父都被我们今天所知。 他们首创的生产技术和文体设备，主要用于整个二十世纪。随后的几年看到平面设计在现代风格获得广泛的接受和应用。第二次世界大战结束后，美国经济的建立更需要平面设计，主要是广告和包装等。移居国外的德国包豪斯设计学院于1937年到芝加哥带来了“大规模生产”极简到美国;引发野火的“现代”建筑和设计。值得注意的名称世纪中叶现代设计包括阿德里安Frutiger ，设计师和Frutiger字体大学;保兰德，从20世纪30年代后期，直到他去世于1996年，采取的原则和适用包豪斯他们受欢迎的广告和标志设计，帮助创造一个独特的办法，美国的欧洲简约而成为一个主要的先驱。平面设计称为企业形象;约瑟夫米勒，罗克曼，设计的海报严重尚未获取1950年代和1960年代时代典型。 从道路标志到技术图表，从备忘录到参考手册，增强了平面设计的知识转让。可读性增强了文字的视觉效果。 设计还可以通过理念或有效的视觉传播帮助销售产品。将它应用到产品和公司识别系统的要素像标志、颜色和文字。连同这些被定义为品牌。品牌已日益成为重要的提供的服务范围，许多平面设计师，企业形象和条件往往是同时交替使用。
10kV小区供配电英文文献及中文翻译
在广州甚至广东的住宅小区电气设计中,一般都会涉及到小区的高低压供配电系统的设计.如10kV高压配电系统图,低压配电系统图等等图纸一大堆.然而在真正实施过程中,供电部门(尤其是供电公司指定的所谓电力设计小公司)根本将这些图纸作为一回事,按其电脑里原有的电子档图纸将数据稍作改动以及断路器按其所好换个厂家名称便美其名曰设计(可笑不?),拿出来的图纸根本无法满足电气设计的设计意图,致使严重存在以下问题:(也不知道是职业道德问题还是根本一窍不通) 1.跟原设计的电气系统货不对板,存在与低压开关柜后出线回路严重冲突,对实际施工造成严重阻碍,经常要求设计单位改动原有电气系统图才能满足它的要求(垄断的没话说). 2.对消防负荷和非消防负荷的供电(主要在高层建筑里)应严格分回路(从母线段)都不清楚,将消防负荷和非消防负荷按一个回路出线(尤其是将电梯和消防电梯,地下室的动力合在一起等等,有的甚至将楼顶消防风机和梯间照明合在一个回路,以一个表计量). 3.系统接地保护接地型式由原设计的TN-S系统竟曲解成"TN-S-C-S"系统(室内的还需要做TN-C,好玩吧?),严格的按照所谓的"三相四线制"再做重复接地来实施,导致后续施工中存在重复浪费资源以及安全隐患等等问题.. ............................(违反建筑电气设计规范等等问题实在不好意思一一例举,给那帮人留点混饭吃的面子算了) 总之吧,在通过图纸审查后的电气设计图纸在这帮人的眼里根本不知何物,经常是完工后的高低压供配电系统已是面目全非了,能有百分之五十的保留已经是谢天谢地了. 所以.我觉得:住宅建筑电气设计,让供电部门走!大不了留点位置,让他供几个必需回路的电,爱怎么折腾让他自个怎么折腾去.. Guangzhou, Guangdong, even in the electrical design of residential quarters, generally involving high-low cell power supply system design. 10kV power distribution systems, such as maps, drawings, etc. low-voltage distribution system map a lot. But in the real implementation of the process, the power sector (especially the so-called power supply design company appointed a small company) did these drawings for one thing, according to computer drawings of the original electronic file data to make a little change, and circuit breakers by their the name of another manufacturer will be sounding good design (ridiculously?), drawing out the design simply can not meet the electrical design intent, resulting in a serious following problems: (do not know or not know nothing about ethical issues) 1. With the original design of the electrical system not meeting board, the existence and low voltage switchgear circuit after qualifying serious conflicts seriously hinder the actual construction, often require changes to the original design unit plans to meet its electrical system requirements (monopoly impress ). 2. On the fire load and fire load of non-supply (mainly in high-rise building in) should be strictly sub-loop (from the bus segment) are not clear, the fire load and fire load of non-qualifying press of a circuit (especially the elevator and fire elevator, basement, etc.
商业建筑外文文献翻译)
Commercial Buildings Abstract: A guide and general reference on electrical design for commercial buildings is provided. It covers load characteristics; voltage considerations; power sources and distribution apparatus; controllers; services, vaults, and electrical equipment rooms; wiring systems; systems protection and coordination; lighting; electric space conditioning; transportation; communication systems planning; facility automation; expansion, modernization, and rehabilitation; special requirements by occupancy; and electrical energy management. Although directed to the power oriented engineer with limited commercial building experience, it can be an aid to all engineers responsible for the electrical design of commercial buildings. This recommended practice is not intended to be a complete handbook; however, it can direct the engineer to texts, periodicals, and references for commercial buildings and act as a guide through the myriad of codes, standards, and practices published by the IEEE, other professional associations, and governmental bodies. Keywords: Commercial buildings, electric power systems, load characteristics 1. Introduction 1.1 Scope This recommended practice will probably be of greatest value to the power oriented engineer with limited commercial building experience. It can also be an aid to all engineers responsible for the electrical design of commercial buildings. However, it is not intended as a replacement for the many excellent engineering texts and handbooks commonly in use, nor is it detailed enough to be a design manual. It should be considered a guide and general reference on electrical design for commercial buildings. 1.2 Commercial Buildings The term “commercial, residential, and institutional buildings”as used in this chapter, encompasses all buildings other than industrial buildings and private dwellings. It includes office and apartment buildings, hotels, schools, and churches, marine, air, railway, and bus terminals, department stores, retail shops, governmental buildings, hospitals, nursing homes, mental and correctional institutions, theaters, sports arenas, and other buildings serving the public directly. Buildings, or parts of buildings, within industrial complexes, which are used as offices or medical facilities or for similar nonindustrial purposes, fall within the scope of this recommended practice. Today’s commercial buildings, because of their increasing size and complexity, have become more and more dependent upon adequate and reliable electric systems. One can better understand the complex nature of modern commercial buildings by examining the systems, equipment, and facilities listed in 1.2.1. 1.2.2 Electrical Design Elements In spite of the wide variety of commercial, residential, and institutional buildings, some electrical design elements are common to all. These elements, listed below, will be discussed generally in this section and in detail in the remaining sections of this recommended practice. The principal design elements considered in the design of the power, lighting, and auxiliary systems include: 1) Magnitudes, quality, characteristics, demand, and coincidence or diversity of loads and load factors 2) Service, distribution, and utilization voltages and voltage regulation 3) Flexibility and provisions for expansion
英文文献及中文翻译
毕业设计说明书 英文文献及中文翻译 学院：专 2011年6月 电子与计算机科学技术软件工程
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英文论文及中文翻译
International Journal of Minerals, Metallurgy and Materials Volume 17, Number 4, August 2010, Page 500 DOI: 10.1007/s12613-010-0348-y Corresponding author: Zhuan Li E-mail: li_zhuan@https://www.360docs.net/doc/7615212338.html, ? University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg 2010 Preparation and properties of C/C-SiC brake composites fabricated by warm compacted-in situ reaction Zhuan Li, Peng Xiao, and Xiang Xiong State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China (Received: 12 August 2009; revised: 28 August 2009; accepted: 2 September 2009) Abstract: Carbon fibre reinforced carbon and silicon carbide dual matrix composites (C/C-SiC) were fabricated by the warm compacted-in situ reaction. The microstructure, mechanical properties, tribological properties, and wear mechanism of C/C-SiC composites at different brake speeds were investigated. The results indicate that the composites are composed of 58wt% C, 37wt% SiC, and 5wt% Si. The density and open porosity are 2.0 g·cm–3 and 10%, respectively. The C/C-SiC brake composites exhibit good mechanical properties. The flexural strength can reach up to 160 MPa, and the impact strength can reach 2.5 kJ·m–2. The C/C-SiC brake composites show excellent tribological performances. The friction coefficient is between 0.57 and 0.67 at the brake speeds from 8 to 24 m·s?1. The brake is stable, and the wear rate is less than 2.02×10?6 cm3·J?1. These results show that the C/C-SiC brake composites are the promising candidates for advanced brake and clutch systems. Keywords: C/C-SiC; ceramic matrix composites; tribological properties; microstructure [This work was financially supported by the National High-Tech Research and Development Program of China (No.2006AA03Z560) and the Graduate Degree Thesis Innovation Foundation of Central South University (No.2008yb019).] 温压-原位反应法制备C / C-SiC刹车复合材料的工艺和性能 李专，肖鹏，熊翔 粉末冶金国家重点实验室，中南大学，湖南长沙410083，中国（收稿日期：2009年8月12日修订：2009年8月28日;接受日期：2009年9月2日） 摘要：采用温压?原位反应法制备炭纤维增强炭和碳化硅双基体(C/C-SiC)复合材