土木工程毕业外文文献及翻译Word文档格式.docx

1、2011级土木工程专业姓 名:XXX学 号:附 件:Structural Systems to resist lateral loads指导老师评语: 该生的外文翻译题目Structural Systems to resist lateral loads该译文基本能与原文关联,思路比较清晰,语句基本通顺,层次清晰,观点表达基本准确。且该生在专业术语、词汇翻译有较高的准确度,叙述层次分明,有较强的逻辑性且格式规范,内容丰富,符合要求。指导教师签名:年 月 日附件1、Commonly Used structural SystemsWith loads measured in tens of tho

2、usands kips, there is little room in the design of high-rise buildings for excessively complex thoughts、 Indeed, the better high-rise buildings carry the universal traits of simplicity of thought and clarity of expression、It does not follow that there is no room for grand thoughts、 Indeed, it is wit

3、h such grand thoughts that the new family of high-rise buildings has evolved、 Perhaps more important, the new concepts of but a few years ago have become commonplace in today s technology、Omitting some concepts that are related strictly to the materials of construction, the most commonly used struct

4、ural systems used in high-rise buildings can be categorized as follows:1. Moment-resisting frames、2. Braced frames, including eccentrically braced frames、3. Shear walls, including steel plate shear walls、4. Tube-in-tube structures、5. Tube-in-tube structures、6. Core-interactive structures、7. Cellular

5、 or bundled-tube systems、Particularly with the recent trend toward more complex forms, but in response also to the need for increased stiffness to resist the forces from wind and earthquake, most high-rise buildings have structural systems built up of combinations of frames, braced bents, shear wall

6、s, and related systems、 Further, for the taller buildings, the majorities are composed of interactive elements in three-dimensional arrays、The method of combining these elements is the very essence of the design process for high-rise buildings、 These combinations need evolve in response to environme

7、ntal, functional, and cost considerations so as to provide efficient structures that provoke the architectural development to new heights、 This is not to say that imaginative structural design can create great architecture、 To the contrary, many examples of fine architecture have been created with o

8、nly moderate support from the structural engineer, while only fine structure, not great architecture, can be developed without the genius and the leadership of a talented architect、 In any event, the best of both is needed to formulate a truly extraordinary design of a high-rise building、While compr

9、ehensive discussions of these seven systems are generally available in the literature, further discussion is warranted here 、The essence of the design process is distributed throughout the discussion、2、Moment-Resisting FramesPerhaps the most commonly used system in low-to medium-rise buildings, the

10、moment-resisting frame, is characterized by linear horizontal and vertical members connected essentially rigidly at their joints、 Such frames are used as a stand-alone system or in combination with other systems so as to provide the needed resistance to horizontal loads、 In the taller of high-rise b

11、uildings, the system is likely to be found inappropriate for a stand-alone system, this because of the difficulty in mobilizing sufficient stiffness under lateral forces、 Analysis can be accomplished by STRESS, STRUDL, or a host of other appropriate computer programs; analysis by the so-called porta

12、l method of the cantilever method has no place in todays technology、Because of the intrinsic flexibility of the column/girder intersection, and because preliminary designs should aim to highlight weaknesses of systems, it is not unusual to use center-to-center dimensions for the frame in the prelimi

13、nary analysis、 Of course, in the latter phases of design, a realistic appraisal in-joint deformation is essential、3、Braced FramesThe braced frame, intrinsically stiffer than the moment resisting frame, finds also greater application to higher-rise buildings、 The system is characterized by linear hor

14、izontal, vertical, and diagonal members, connected simply or rigidly at their joints、 It is used commonly in conjunction with other systems for taller buildings and as a stand-alone system in low-to medium-rise buildings、While the use of structural steel in braced frames is common, concrete frames a

15、re more likely to be of the larger-scale variety、Of special interest in areas of high seismicity is the use of the eccentric braced frame、Again, analysis can be by STRESS, STRUDL, or any one of a series of two or three dimensional analysis computer programs、 And again, center-to-center dimensions ar

16、e used commonly in the preliminary analysis、 4、Shear wallsThe shear wall is yet another step forward along a progression of ever-stiffer structural systems、 The system is characterized by relatively thin, generally （but not always） concrete elements that provide both structural strength and separati

17、on between building functions、In high-rise buildings, shear wall systems tend to have a relatively high aspect ratio, that is, their height tends to be large compared to their width、 Lacking tension in the foundation system, any structural element is limited in its ability to resist overturning mome

18、nt by the width of the system and by the gravity load supported by the element、 Limited to a narrow overturning, One obvious use of the system, which does have the needed width, is in the exterior walls of building, where the requirement for windows is kept small、Structural steel shear walls, genera

19、lly stiffened against buckling by a concrete overlay, have found application where shear loads are high、 The system, intrinsically more economical than steel bracing, is particularly effective in carrying shear loads down through the taller floors in the areas immediately above grade、 The sys tem ha

20、s the further advantage of having high ductility a feature of particular importance in areas of high seismicity、The analysis of shear wall systems is made complex because of the inevitable presence of large openings through these walls、 Preliminary analysis can be by truss-analogy, by the finite ele

21、ment method, or by making use of a proprietary computer program designed to consider the interaction, or coupling, of shear walls、5、Framed or Braced TubesThe concept of the framed or braced or braced tube erupted into the technology with the IBM Building in Pittsburgh, but was followed immediately w

22、ith the twin 110-story towers of the World Trade Center, New York and a number of other buildings 、The system is characterized by three dimensional frames, braced frames, or shear walls, forming a closed surface more or less cylindrical in nature, but of nearly any plan configuration、 Because those

23、columns that resist lateral forces are placed as far as possible from the cancroids of the system, the overall moment of inertia is increased and stiffness is very high、The analysis of tubular structures is done using three-dimensional concepts, or by two- dimensional analogy, where possible, whiche

24、ver method is used, it must be capable of accounting for the effects of shear lag、The presence of shear lag, detected first in aircraft structures, is a serious limitation in the stiffness of framed tubes、 The concept has limited recent applications of framed tubes to the shear of 60 stories、 Design

25、ers have developed various techniques for reducing the effects of shear lag, most noticeably the use of belt trusses、 This system finds application in buildings perhaps 40stories and higher、 However, except for possible aesthetic considerations, belt trusses interfere with nearly every building func

26、tion associated with the outside wall; the trusses are placed often at mechanical floors, mush to the disapproval of the designers of the mechanical systems、 Nevertheless, as a cost-effective structural system, the belt truss works well and will likely find continued approval from designers、 Numerou

27、s studies have sought to optimize the location of these trusses, with the optimum location very dependent on the number of trusses provided、 Experience would indicate, however, that the location of these trusses is provided by the optimization of mechanical systems and by aesthetic considerations, a

28、s the economics of the structural system is not highly sensitive to belt truss location、6、Tube-in-Tube StructuresThe tubular framing system mobilizes every column in the exterior wall in resisting over-turning and shearing forces、 The termtube-in-tubeis largely self-explanatory in that a second ring

29、 of columns, the ring surrounding the central service core of the building, is used as an inner framed or braced tube、 The purpose of the second tube is to increase resistance to over turning and to increase lateral stiffness、 The tubes need not be of the same character; that is, one tube could be f

30、ramed, while the other could be braced、In considering this system, is important to understand clearly the difference between the shear and the flexural components of deflection, the terms being taken from beam analogy、 In a framed tube, the shear component of deflection is associated with the bendin

31、g deformation of columns and girders （i、e, the webs of the framed tube） while the flexural component is associated with the axial shortening and lengthening of columns （i、e, the flanges of the framed tube）、 In a braced tube, the shear component of deflection is associated with the axial deformation

32、of diagonals while the flexural component of deflection is associated with the axial shortening and lengthening of columns、Following beam analogy, if plane surfaces remain plane （i、e, the floor slabs）,then axial stresses in the columns of the outer tube, being farther form the neutral axis, will be substantially larger than the axial stresses in the inner tube、 However, in the tube-in-tube design, when optimized, the axial stresses in the inner ring of columns may be as high, or eve