1、高层建筑与钢结构外文翻译 毕业设计（论文） 外文翻译2013年5 月 22日High-rise Building and Steel ConstructionHUi Wei-jun1，DONG Han1，WENG Yu-ging2，CHEN Si-lian1，WANG Mao-giu1（1.Central iron & Steel Research institute，Beijing 100081，China；Although there have been many advancements in building construction technology in general. Sp
2、ectacular archievements have been made in the design and construction of ultrahigh-rise buildings. The early development of high-rise buildings began with structural steel framing. Reinforced concrete and stressed-skin tube systems have since been economically and competitively used ina number of st
3、ructures for both residential and commercial purposes. The high-rise buildings ranging from 50 to 110 stories that are being built all over the United States are the result of innovations and development of new structual systems. Greater height entails increased column and beam sizes to make buildin
4、gs more rigid so that under wind load they will not sway beyond an acceptable limit. Excessive lateral sway may cause serious recurring damage to partition sceilings. and other architectural details. In addition excessive sway may cause discomfort to the occupants of the building because the irperce
5、ption of such motion. Structural systems of reinforced concrete as well as steel take full advantage of inherent potential stiffness of the total building and therefore require additional stiffening to limit the sway. In a steel structure for example the economy can be defined in terms of the total
6、average quantity of steel per square foot of floor area of the building. Curve A in Fig .1 represents the average unit weight of a conventional frame with increasing numbers of stories. Curve B represents the average steel weight if the frame is protected from all lateral loads. The gap between the
7、upper boundary and the lower boundary represents the premium for height for the traditional column-and-beam frame. Structural engineers have developed structural systems with a view to eliminating this premium. Systems in steel. Tall buildings in steel developed as a result of several types of struc
8、tural innovations. The innovations have been applied to the construction of both office and apartment buildings. Frame with rigid belt trusses. In order to tie the exterior columns of a frame structure to the interior vertical trusses a system of rigid belt trusses at mid-height and at the top of th
9、e building may be used. A good example of this system is the First Wisconsin Bank Building1974in Milwaukee. Framed tube. The maximum efficiency of the total structure of a tall building for both strength and stiffness to resist wind load can be achieved only if all column element can be connected to
10、 each other in such a way that the entire building acts as a hollow tube or rigid box in projecting out of the ground. This particular structural system was probably used for the first time in the 43-story reinforced concrete DeWitt Chestnut Apartment Building in Chicago. The most significant use of
11、 this system is in the twin structural steel towers of the 110-story World Trade Center building in New York Column-diagonal truss tube. The exterior columns of a building can be spaced reasonably far apart and yet be made to work together as a tube by connecting them with diagonal members interesti
12、ng at the centre line of the columns and beams. This simple yet extremely efficient system was used for the first time on the John Hancock Centre in Chicago using as much steel as is normally needed for a traditional 40-story building. Bundled tube. With the continuing need for larger and taller bui
13、ldings the framed tube or the column-diagonal truss tube may be used in a bundled form to create larger tube envelopes while maintaining high efficiency. The 110-story Sears Roebuck Headquarters Building in Chicago has nine tube bundled at the base of the building in three rows. Some of these indivi
14、dual tubes terminate at different heights of the building demonstrating the unlimitedarchitectural possibilities of this latest structural concept. The Sears tower at a height of 1450ft442m is the worlds tallest buildingStressed-skin tube system. The tube structural system was developed for improvin
15、g. The resistance to lateral forces wind and earthquake and the control of drift lateral building movement in high-rise building. The stressed-skin tube takes the tube system a step further. The development of the stressed-skin tube utilizes the faade of the building as a structural element which ac
16、ts with the framed tube thus providing an efficient way of resisting lateral loads in high-rise buildings and resulting in cost-effective column-free interior space with a high ratioof net to gross floor area. Because of the contribution of the stressed-skin faade the framed members of the tuberequi
17、re less mass and are thus lighter and less expensive. All the typical columns and spandrelbeams are standard rolled shape sminimizing the use and cost of special built-up members. The depth requirement for the perimeter spandrel beams is also reduced and the need for up setbeams above floors which w
18、ould encroach on valuable space is minimized. The structural system has been used on the 54-story One Mellon Bank Center in Pittburgh. Systems in concrete. While tall buildings constructed of steel had an early start development of tall buildings of reinforced concrete progressed at a fast enough ra
19、te to provide a competitive chanllenge to structural steel systems for both office and apartment buildings. Framed tube. As discussed above the first framed tube concept for tall buildings was usedfor the 43-story DeWitt Chestnut Apartment Building. In this building exterior columns were spaced at 5
20、.5ft 1.68m centers and interior columns were used as needed to support the 8-in .-thick 20-m flat-plate concrete slabs. Tube in tube. Another system in reinforced concrete for office buildings combines the traditional shear wall construction with an exterior framed tube. The system consists of an ou
21、t erframed tube of very closely spaced columns and an interior rigid shear wall tube enclosing the central service area. The system Fig .2 known as the tube-in-tube system made it possible to design the worlds present tallest 714ft or 218mlightweight concrete building the 52-storyOne Shell Plaza Bui
22、lding in Houston for the unit price of a traditional shear wall structure of only 35 stories. Systems combining both concrete and steel have also been developed an example of which is the composite system developed by skid more Owings ampMerril in which an exteri.An optical micrograph and a phase ma
23、p of the as-received base material are shown in Fig. 4. The base material has atypical microstructure of wrought duplex stainless steels con-sisting of ferrite matrix with austenite islands. OIM analysis revealed that the austenite islands contained a higher number of grain boundaries (mostly twin t
24、ype boundaries) than the ferrite. OIM analysis also revealed that the ferrite content was about 51%. Average grain sizes of austenite and ferrite phases in the base material were about 4.3 and 5.1 _m, respectively. Optical microstructures of regions “A,” “B,” “C” and “D” shown in Fig. 3 are indicate
25、d in Fig. 5. Region B lies on the weld centre, and region D is located on the border of the stir zone and TMAZ. Regions A and C are located around 2 mm away from the weld centre at the retreating and advancing sides, respectively. Region B has the microstructure consist-ing of ferrite matrix with th
26、e more elongated austenite islands. Austenite islands of region B look finer than those of the base material. Region A has the similar microstructure to regionB, while region C seems to contain finer austenite islands than region B. Distribution of the austenite islands is finest in the stir zone at
27、 the advancing side, as shown in micrograph of region D. In this region, D, the austenite in the stir zone exhibits an average grain size of lying immediately adjacent to elongated austenite islands in the TMAZ. Phase maps of regions, CEN and in the weld are shown in All regions consist of a ferrite
28、 matrix with the austenite islands similar to that of the base material. Dis-tribution of the austenite islands in regions and CEN is similar to that in the base material, but the austenite islandscontain more grain boundaries than the base material. The grain size profile ( Fig. 8) showed that the
29、austenite and ferrite grains in the stir zone were smaller than those in the base material. Additionally, the phase maps showed that both the austenite and ferrite phases in the stir zone did not exhibit a heavily deformed microstructure, e.g. many low angle grain boundaries. Both the grain size pro
30、file and phase maps suggest that dynamic recrystallisation occurred both in the austenite and ferrite phases during FSW. It is gener-ally known that dynamic recrystallisation easily occurs in the austenitic stainless steels, while ferritic steels hardly experi-ence dynamic recrystallisation because
31、the ferrite phase has a high stacking fault energy.In the case of the duplex stainless steels, however, de-formation is localized in the ferrite matrix at high temper-atures, because the ferrite phase is relatively weaker than the austenite. Consequently, the recrystallised grains are often formed i
32、n ferrite phase more easily than in austenite phase. Some research suggests that the recrystallised grains in the ferrite phase are formedBy continuous dynamic recrystallisation, which is charac-terized by strain-induced progressive rotation of subgrains with little boundary migration. In the present study, the du-plex stainless steel experienced plastic deformation by therotating tool at relatively high temperatures during FSW. As such, it is likely that the ferrite matrix in the stir zone under-goes continuous dynamic recrystallisation through the samescenario.
