Large-scale Structure Of The Local Nonlinear Stochastic Earthquake Response Analysis

In this paper seismic analysis method of large complex structures such as bridges, tall buildings, subjected to stationary random ground excitations is investigated for which the non-linear elasto-plastic characters of some components is taken into account. The Bouc-Wen differential equation model is used in modeling the hysteretic characteristics of these components. The PEM(Pseudo Excitation Method) combined with the ELM(equivalent linearization method) is used to analyze the non-linear random vibration of such structures. The shear-type non-linear hysteretic system subjected to stationary excitation and local non-linear random vibration of engineering structure under earthquake excitation are studied.The research work about the shear-type hysteretic system includes: i ) Random response of SDOF hysteretic system under variant excitation intensities are analyzed using the PEM combined with the ELM. The results are all in good agreement with those of the Liapunov differential equations and the Monte-Carlo simulation; ii ) The stationary random responses of such MDOF hysteretic systems subjected to earthquake excitation under variant non-linear coefficients are studied using the PEM combined with ELM; The results are compared with those calculated by using integration, the difference is not obvious.The research work about the local non-linear random vibration of engineering structure under earthquake excitation includes; Discrete hinge model combined with the PEM and the ELM is used to solve such non-linear problem which the bend-type hysteretic effect of some components is taken into account. Algorithm above has been implemented in finite element program DDJ-W, and can analyze non-linear random response of 3-D structure which has complex boundary conditions under earthquake excitation. Practical bridges of engineering are calculated and the results are reasonable.Finally, the possibility of engineering application and accuracy of the PEM in analyzing the random response of non-linear structures are discussed based on the work outlined above. Method presented in this paper makes full use of the merits of the PEM, i.e. its high efficiency and accuracy in solving the linear random vibration of complex structures. The solution of the original nonlinear problem is reasonably approximated by means of a series of random vibration analyses for the linearized structure using the pseudo excitation method.