外文翻译及外文原文.docx

1、外文翻译及外文原文外文翻译要求： 1、外文资料及毕业设计（论文）选题密切相关，译文准确、质量好。 2、阅读2篇幅以上（10000字符左右）的外文资料，完成2篇不同文章的共2000汉字以上的英译汉翻译3、外文资料可以由指导教师提供，外文资料原则上应是外国作者。严禁采用专业外语教材文章。4、排序：“一篇中文译文、一篇外文原文、一篇中文译文、一篇外文原文”。插图内文字及图名也译成中文。5、标题及译文格式（字体、字号、行距、页边距等）及论文格式要求相同。下页附：外文翻译及原文参考格式英文翻译 (黑体、四号、顶格)外文原文出处：(译文前列出外文原文出处、作者、国籍，译文后附上外文原文)ASHRAE Ha

2、ndbookRefrigeration.CHAPTER3 .SYSTEM Practices for ammonia 3.1 System Selection 3.2 Equipment 3.10 Reciprocating Compressors第3章 氨制冷系统的实施3.1 系统选择 在选择一个氨制冷系统设计时，须要考虑一些设计决策要素，包括是否采用（1）单级压缩（2）带经济器的压缩（3）多级压缩（4）直接蒸发（5）满液式（6）液体再循环（7）载冷剂。单级压缩系统基本的单级压缩系统由蒸发器、压缩机、冷凝器、储液器（假如用的话）和制冷剂控制装置（膨胀阀、浮球阀等）。1997 ASHRAE手册

3、“原理篇”中的第一章讨论了压缩制冷循环。图1.壳管式经济器的布置英文原文 (黑体、四号、顶格)英文翻译2（黑体，四号，顶格）外文原文出处：（黑体，四号，顶格）P. Fanning. Nonlinear Models of Reinforced and Post-tensioned Concrete Beams. Lecturer, Department of Civil Engineering, University College Dublin. Received 16 Jul 2001.非线形模型钢筋和后张法预应力混凝土梁摘要:商业有限元软件一般包括混凝土在荷载做用下非线性反应的专用数值模

4、型。这些模型通常包括混凝土开裂时的抗拉强度，混凝土受压缩区域可塑性的运算法则以及各种方法的详细说明，梁内部配筋的分布情况。本文主要讨论的就是被ANSYS软件采用的数字模型。通过对普通钢筋混凝土梁，后张法预应力混凝土T型梁的荷载-挠度反应对比实验确定适当数字模型。关键字:混凝土；后张法；有限元模型。2 测试梁 在普通混凝土梁和后张法预应力钢筋混凝土梁上的最终负载测试结果被用来评估是否适合用ANSYS软件建立钢筋混凝土模型来预测钢筋混凝土梁。3.0米普通钢筋混凝土梁长为3.0米梁的横截面，图1为截面配筋图,三根直径为12毫米的钢筋和两根直径为12毫米钢筋被包藏在张力区域作为受压钢筋。直径为6毫米，

5、相邻间距为125毫米箍筋作为抗剪区域的受拉钢筋。对两根宽为2.8m的梁分别进行对称和非对称加载实验，4个加载点位于梁上，加载点及梁边缘间的距离为0.3M，通过位移控制集中荷载的大小，直到梁破坏为止。通过梁的压坏实验，根据英国标准查出的混凝土轴心抗拉强度和轴心抗压强度标准值(ft = 5.1N/mm2 ， fc = 69.0N/mm2)，及混凝土的杨氏模量 (39,200 N/mm2)等数据算出理论模型。通过拉伸试验保证样品梁的非线性的塑性反应能在理论模型上准确模仿,梁的配筋应能保证梁的整体稳定性。 受压钢筋为2 根直径为12mm, fy=460N/mm2的钢筋箍筋为直径6mm ,fy=250N

6、/mm2的钢筋(箍筋间距为125mm)受拉钢筋为3根直径为12mmfy=460N/mm2的钢筋图1：3.0米梁的横截面详图9.0米预应力混凝土梁9.0米预应力混凝土梁的测试是在斯洛文尼亚首都卢布尔雅那的土木工程研究所完成的，详图示于图2 。T型梁的翼缘宽1.1米、厚0.08米，其有效腹板I型梁的翼缘宽0.29米、厚0.6米。除了普通的配筋外，在浇筑好混凝土构件上预留75.08毫米网格的孔道，将预应力筋穿入孔道后，在孔道内灌浆使钢筋和混凝土构成一个整体。通过对梁进行拉伸实验、钢筋的强度和刚度试验，混凝土的有关材料性能，线性及非线性等数据确定梁的理论模型。在梁上加载集中荷载直到梁破坏，记录下混凝土

7、梁上的应变片册出挠度和应力等数据。负载情况如图3所示，在所有情况下，集中荷载P1和P2之间以外的区域上布置均布荷载。图2：后张法预应力梁的长和横截面模型图3：荷载布置6 结论3.0米普通钢筋混凝土梁和9.0米后张法预应力混凝土梁，建立在ANSYS V5.5的有限元模型已经准确记录了梁非线性弯曲直到破坏的应变反应。梁上的裂缝表明了混凝土开裂及配筋率有关。通过对试验梁的研究发现，控制箍筋密度和准确定位内部钢筋是对梁加固的一种方式。因此，普通钢筋混凝土梁的所有内部钢筋要按照理论模型分配，后张法预应力梁的后张筋以及分布钢筋也应按照模型分配。总而言之检测钢筋混凝土弯曲破坏的梁可以用一个适当的理论模型来表

8、示。此外，当必须用给定的荷载精确地预测钢筋混凝土系统的变形时，应引起设计师重视。英文原文2（黑体，四号，顶格）Nonlinear Models of Reinforced and Post-tensioned Concrete Beams P. FanningLecturer, Department of Civil Engineering, University College DublinEarlsfort Terrace, Dublin 2, Ireland.Email: paul.Received 16 Jul 2001; revised 8 Sep 2001; accepted 12

9、 Sep 2001.AbstractCommercial finite element software generally includes dedicated numerical models for the nonlinear response of concrete under loading. These models usually include a smeared crack analogy to account for the relatively poor tensile strength of concrete, a plasticity algorithm to fac

10、ilitate concrete crushing in compression regions and a method of specifying the amount, the distribution and the orientation of any internal reinforcement. The numerical model adopted by ANSYS is discussed in this paper. Appropriate numerical modelling strategies are recommended and comparisons with

11、 experimental load-deflection responses are discussed for ordinary reinforced concrete beams and post-tensioned concrete T-beams.Keywords Concrete; post-tensioning; finite element modelling.2. Test case beamsResults of ultimate load tests on ordinarily reinforced and post-tensioned concrete beams we

12、re used to assess the suitability of the reinforced concrete model implemented in ANSYS in predicting the ultimate response of reinforced concrete beams. 3.0m long Ordinarily Reinforced Concrete BeamsA cross section through the 3.0m long beams, Figure 1, illustrates the internal reinforcement. Three

13、 12mm diameter steel bars were included in the tension zone with two 12mm steel bars as compression steel. Ten shear links, formed from 6mm mild steel bars, were provided at 125mm centres for shear reinforcement in the shear spans. Two beams were tested each of which were simply supported with a cle

14、ar span of 2.8m and loaded symmetrically and monotonically, under displacement control, in four point bending, with point loads 0.3m either side of the mid-span location, to failure. Cylinder splitting and crushing tests on cored samples of the beams, in accordance with the British Standards, were u

15、ndertaken to identify the uni-axial tensile and compressive strengths of the concrete, (ft = 5.1N/mm2 and fc = 69.0N/mm2 respectively), and the Youngs Modulus of the concrete , (39,200 N/mm2), for inclusion in the numerical models. Tensile tests on samples of the reinforcing bars and shear links wer

16、e also undertaken such that their nonlinear plastic response could be accurately simulated in the numerical models. 9.0m long Third Scale Prestressed Beams A cross section and elevation of third scale models of 30m long prestressed concrete beams tested at the Slovenian National Building and Civil E

17、ngineering Institute, Ljubljana, Slovenia are shown in Figure 2. The flange of the T-beam is 1.1m wide and 0.08m deep while the web is effectively an I-beam with a flange width of 0.29m and an overall depth of 0.6m. In addition to ordinary reinforcing bars, three grouted 0.6 (15.2 mm) tendons, each

18、composed of 75.08mm diameter wires, were used to post-tension each beam. Tensile tests on the reinforcing bars and tendons and strength and stiffness tests on the concrete identified the relevant material properties, linear and nonlinear, for the numerical model.The beam was loaded to failure while

19、deflection and strain data, on the external concrete surfaces and on the individual cables, were monitored. The load arrangement is illustrated in Figure 3 and in all cases the uniformly distributed loading was applied initially with the point loads P1 and P2 being applied in subsequent increments u

20、ntil the ultimate load of the beam was reached.Figure 1: Cross section details for the 3.0m beamsFigure 2: Elevation and cross-section of the model post-tensioned beamFigure 3: Loading arrangement6. ConclusionsFinite element models of 3.0m ordinarily reinforced concrete beams and 9.0m post-tensioned

21、 concrete beams, constructed in ANSYS V5.5 using the dedicated concrete element have accurately captured the nonlinear flexural response of these systems up to failure.The dedicated element employs a smeared crack model to allow for concrete cracking with the option of modelling the reinforcement in

22、 a distributed or discrete manner. It was found that the optimum modelling strategy, in terms of controlling mesh density and accurately locating the internal reinforcement was to model the primary reinforcing in a discrete manner. Hence for ordinary reinforced concrete beams all internal reinforcem

23、ent should be modelled discretely and for post-tensioned beams the post-tensioning tendons should be modelled discretely with any other additional reinforcement modelled in a distributed manner.In conclusion the dedicated smeared crack model is an appropriate numerical model for capturing the flexural modes of failure of reinforced concrete systems. In addition it should be particularly attractive to designers when they are required to accurately predict the deflection of a reinforced concrete system, for a given load, in addition to its ultimate strength.