外文翻譯--用靜力彈塑性分析方法分析方鋼管混凝土框架結(jié)構(gòu)抗震性能（英文版）

1、TSINGHUA SCIENCE AND TECHNOLOGY ISSN 1007-0214 20/21 pp124-130 Volume 11, Number 1, February 2006 Push-Over Analysis of the Seismic Behavior of a Concrete-Filled Rectangular Tubular Frame Structure* NIE Jianguo (聶建國

2、) **, QIN Kai (秦 凱), XIAO Yan (肖 巖) ? Department of Civil Engineering, Tsinghua University, Beijing 100084, China; ? Department of Civil Engineering, University of Southern California, Los Angeles, CA 90089, USA Abstr

3、act: To investigate the seismic behavior of concrete-filled rectangular steel tube (CFRT) structures, a push-over analysis of a 10-story moment resisting frame (MRF) composed of CFRT columns and steel beams was conducted

4、. The results show that push-over analysis is sensitive to the lateral load patterns, so the use of at least two load patterns that are expected to bound the inertia force distributions is recom-mended. The - M φ curve

5、s and - N M interaction surfaces of the CFRT columns calculated either by Han’s formulae or by the USC-RC program (reinforced concrete program put forward by University of Southern Califonia) are suitable for future pu

6、sh-over analyses of CFRT structures. The - P ? effect affects the MRF seismic behavior seriously, and so should be taken into account in MRF seismic analysis. In addition, three kinds of RC structures were analyzed to

7、allow a comparison of the earthquake resistance behavior of CFRT structures and RC structures. The results show that the ductility and seismic performance of CFRT struc-tures are superior to those of RC structures. Conse

8、quently, CFRT structures are recommended in seismic regions. Key words: concrete-filled rectangular steel tube; push-over analysis; capacity curve; reinforced concrete Introduction Over the past twenty years the static p

9、ush-over proce-dure has been presented and developed by several au-thors, including Saiidi and Sozen[1], Fajfar and Gasper-sic[2], Bracci et al.[3], amongst others. This method is also described and recommended as a tool

10、 for design and assessment purposes for the seismic rehabilitation of existing buildings[4]. The purpose of push-over analysis is to evaluate the expected performance of a structural system by estimating its strength and

11、 defor-mation demands in design earthquakes by means of a static inelastic analysis, and by comparing these de-mands to available capacities at the performance levels. Push-over analysis is basically a nonlinear static a

12、nalysis that is performed by imposing an assumed dis-tribution of lateral loads over the height of a structure and increasing the lateral loads monotonically from zero to the ultimate level corresponding to the incipient

13、 collapse of the structure. The gravity load remains con-stant during the analysis. Push-over analysis is very useful in estimating the following characteristics of a structure: 1) the capacity of the structure as repres

14、ented by the base shear versus top displacement graph; 2) the maximum rotation and ductility of critical members; 3) the distribution of plastic hinges at the ultimate load; and 4) the distribution of damage in the struc

15、ture, as expressed in the form of local damage indices at the ul-timate load. Although push-over analyses of reinforced ﹡Received: 2004-06-30; revised: 2004-11-07 Supported by the Overseas Youth Cooperative Foundation of

16、 the National Natural Science Foundation of China (No. 50128807) ﹡ ﹡To whom correspondence should be addressed. E-mail: niejg@mail.tsinghua.edu.cn; Tel: 86-10-62772457 Tsinghua Science and Technology, February 2006, 11(

17、1): 124-130 126 structure are shown in Fig. 1. The SAP2000 program is used for the push-over analysis of the CFRT struc-ture. The floors of the building are 100 mm deep, and are modeled as shell elements in SAP2000. The

18、di-mensions and material properties of the structural members are shown in Table 1. In SAP2000 the CFRT columns and steel beams are modeled as frame elements. Table 1 Dimensions and material properties of the strutural

19、members of the CFRT structure Story No. Steel beams (mm) CFRT columns (mm) 1,2 700 300 13 24 700 20 3 700 300 13 24 700 18 4-6 692 300 13 20 700 18 7-10 692 300 13 20 700 16 Material property Q345 Q345 C40 1.1

20、 Hinge properties In frame structures plastic hinges usually form at the ends of beams and columns under earthquake action. For beam elements, plastic hinges are mostly caused by uniaxial bending moments, whereas for col

21、umn elements, plastic hinges are mostly caused by axial loads and biaxial bending moments. Therefore, in push-over analysis different types of plastic hinges should be applied for the beam elements and the col-umn elemen

22、ts separately. In SAP2000, the M3 hinge is used to simulate the plastic hinge caused by uniaxial moment, so user-defined M3 hinges are applied to the steel beams in this model. To calculate moment-rotation curves of the

23、steel beams, the following assumptions are adopted: 1) a classical bilinear isotropic hardening model is applied to represent the stress-strain behav-ior of the steel beam; and 2) plane sections remain plane. The typical

24、 M-φ curve for the steel beams is shown in Fig. 2. Fig. 2 M-φ φ φ φ curve of steel beams in the 1st-3rd stories Similarly, the PMM hinge is used by SAP2000 to simulate the plastic hinge caused by axial load and biaxia

25、l bending moments. User-defined PMM hinges are therefore applied to the CFRT columns in this model. The M-φ curves and N-M interaction surfaces of the CFRT columns are calculated using both Han’s formulae[10] and the USC

26、-RC program(RC program put forward by University of Southern California), for the purpose of comparison. The typical N?M interac-tion surface and M-φ curve of the CFRT columns are shown in Fig. 3. Fig. 3 - N M intera

27、ction surface and - M φ φ φ φ curve of CFRT columns in the 1st and 2nd stories 1.2 Lateral load patterns The lateral load patterns are intended to represent the distribution of inertia forces in a design earthquake[11]

28、. It is clear that the distribution of inertia forces will vary with the severity of the earthquake (i.e., the extent of inelastic deformations) and with time during an earthquake. Since no single load pattern can captur

29、e the variations in the local demands expected in a de-sign earthquake, two lateral load patterns that are ex-pected to bound the inertia force distributions are used in this push-over analysis. One is an inverted triang