两层钢管混凝土组合框架结构抗震性能试验研究

拟动力试验方法最早是由日本学者于1975年提出的,它综合了拟静力试验、振动台试验和时程反应数值分析的特点,来实际模拟结构损伤、刚度变化产生的非线性行为,近年来已得到广泛应用。本文通过对一榀由钢管混凝土柱和组合楼盖经由半刚性连接构成的组合框架1/3比例模型的拟静力、拟动力试验和弹塑性地震反应分析,研究此类结构在地震作用下的动力响应、恢复力特性和耗能性能;其中输入的地震波先采用ElCentro波,后采用Kobe波,模拟结构经历不同的地震作用。实测显示:累积损伤导致结构底层刚度的较大弱化,结构基频下降;钢管混凝土柱屈服,角区混凝土开裂,结构呈现较好的变形延性。本文还根据实测结果建立了一个预测组合框架结构在地震作用下弹塑性性能的分析模型,理论计算和试验结果基本吻合;实验和计算表明钢-混凝土组合框架结构具有良好的抗震性能。

Experimental Research on Seismic Be havior of a Two-story Concrete Fille d Steel Tubular Composite Frame

The pseudodynamic test method was fi rst proposed and used by Japanese researchers in 1975.It combines the features of quasi-static testing,s haking table testing,and numerical time history analysis in order to realistically simulate the nonlinear behavior of structure s that exhibit the variation of stiff ness caused by damage incurred durin g the excita-tion,and it is now being widely used i n practice.Seismic evaluation of a 1/3-scaled model of a two-story composite steel-concrete frame was performed by the pseudodynamic,pseudo-static,and monotonic testing.The specim en con-sisted of concrete filled circular s teel tubular column and steel-concrete floor slabs.The connection of beam and column was semi-rigidly connected.The dyn amic responses,the characteristic s of recovered forces,and the energy consuming behavior of the structural system under earthquake loading were studied.The specimen was first subjected to three tests of increasing magnitude based on the El Centro ground motion,and then two tests based on the Kobe waves,which simulated different seismic loadin gs on the structure.The experiments displayed that the accumulated dama ge caused much more weakening of stiffness in t he lower story and the decreasing of t he first frequency of the frame.The t ests produced the yield of the concrete fi lled steel tubular columns and the cracking of concrete at the corners.It is shown that concrete filled steel tubular c omposite frame structure exhibits s ufficient ductility and strength.I n this paper,an analytical model was developed to pr edict the elastoplastic behavior of the composite frame under seismic lo ading based on the experiments.The values predi cted by the calculation model were fo und to correlate well with the measur ed data.The experiments and the calculation demonstrate that the composite fram e has adequate response to earthquak e loading even in areas of high earthquake inte nsity.