Abstract:Actual seismic records show that seismic action is an obviously non-stationary random process. Under the action of strong earthquake, the structure will exhibit hysteretic behavior, and even degradation behavior. An improved Bouc-Wen model, which can simulate structural degradation and pinching effect, is adopted to simulate the behaviors of structures under earthquake action. With equivalent linearization method, random response of the improved Bouc-Wen system under non-stationary excitation is analyzed. The solutions are further verified with Monte Carlo method. Results present that seismic intensity, structural degradation and pinching effect significantly influence the structural response and accumulated hysteretic energy dissipation. Finally, a wooden bent structure under non-stationary seismic excitation is taken as an example. The results indicate that the mean of the accumulated hysteretic energy dissipation and the RMS(root mean squared)displacement increases with the rise of earthquake intensity. Degradations of strength and stiffness obviously increase the RMS displacement of the system, but influence the hysteretic energy dissipation slightly. Pinching effect significantly increases the RMS displacement of the system, and reduces the mean cumulative hysteretic energy dissipation. On the other hand, the agreement between approximate solution and simulated ones seems not good if degrading or pinching effect exist, but still satisfies engineering requirements.
[1] AMIN M, ANG A H S. Nonstationary Stochastic model of earthquake motion [J]. Journal of Engineering Mechanics, ASCE, 1968, 94(EM2): 559-583.
[2] BABER T T, NOORI M N. Modeling general hysteresis behavior and random vibration application [J]. Journal of Vibration, Acoustics, Stress, and Reliability in Design, 1986, 108(4): 411-420.
[3] BABER T T, NOORI M N. Random vibration of degrading pinching systems [J]. Journal of Engineering Mechanics. ASCE, 1985, 111(8): 1010-1026.
[4] JIN X L, HUANG Z L, LEUNG A Y T. Nonstationary seismic responses of structure with nonlinear stiffness subject to modulated Kanai-Tajimi excitation [J]. Earthquake Engineering & Structural Dynamics, 2012, 41(2): 197-210.
[5] TUBALDI E, KOUGIOUMTZOGLOU I A. Nonstationary stochastic response of structural systems equipped with nonlinear viscous dampers under seismic excitation [J]. Earthquake Engineering & Structural Dynamics, 2015, 44(1): 121-138.
[6] 胡晓斌, 江卫波. 自复位单自由度体系随机地震响应分析[J]. 振动与冲击, 2016, 35(16): 152-157.
HU Xiaobin, JIANG Weibo. A random seismic response analysis of self-centering SDOF systems [J]. Journal of Vibration and Shock, 2016, 35(16): 152-157.
[7] 李创第, 黄天立, 李暾, 等. 隔震结构非线性随机地震响应分析的复模态法 [J]. 振动与冲击, 2004, 23(1): 21-26.
LI Chuangdi, HUANG Tianli, LI Tun, et al. Complex modal method for analysis of non-linear randaom earthquake response of structures with base isolation [J]. Journal of Vibration and Shock, 2004, 23(1): 21-26.
[8] 孙臻, 王曙光, 王赟玉, 等. 高层隔震结构非平稳随机地震响应与动力可靠度分析 [J]. 建筑结构学报, 2011, 32(12): 210-216.
SUN Zhen, WANG Shuguang, WANG Yunyu, et al. Non-stationary random response and dynamic reliability of high-rise seismic isolated structure [J]. Journal of Building Structures, 2011, 32(12): 210-216.
[9] PARK Y J, WEN Y K, ANG A H S. Random vibration of hysteretic system under Bi-directional ground motion [J]. Earthquake Engineering & Structural Dynamics, 1986, 14(4): 543-557.
[10] JANGID R S. Response of SDOF system to non-stationary earthquake excitation [J]. Earthquake Engineering & Structural Dynamics, 2004, 33(15): 1417-1428.
[11] 谢启芳, 赵鸿铁, 薛建阳, 等. 中国古建筑木结构榫卯节点加固的试验研究 [J]. 土木工程学报, 2008, 41(1): 28-34.
XIE Qifang, ZHAO Hongtie, XUE Jianyang, et al. An experimental study on the strengthening of mortise-tenon joints in ancient Chinese wooden buildings [J]. China Civil Engineering Journal, 2008, 41(1): 28-34.
[12] 欧进萍, 牛荻涛. 设计用随机地震动的模型及其参数确 [J]地震工程与工程振动, 1991(3):45-54.
OU Jinping, NIU Ditao. Design uses stochastic ground motion model and its parameters to determine [J]. Earthquake Engineering and Engineering Vibration, 1991(3): 45-54.
[13] 刘俊, 陈林聪, 孙建桥. 随机激励下滞迟系统的稳态响应闭合解 [J]. 力学学报, 2017, 49(03): 685-692.
LIU Jun, CHEN Lincong, SUN Jianqiao. The closed-form solution of steady state response of hysteretic system under stochastic excitation [J]. Chinese Journal of Theoretical and Applied Mechanics, 2017, 49(03): 685-692.
[14] 余波, 宁超列. 工程结构非弹性地震动力反应分析的BWBN模型 [J]. 工程力学, 2017(S1): 265-275.
YU Bo, NING Chaolie. Recent progress on BNBW model for structural inelastic seismic response analysis [J]. Engineering Mechanics, 2017(S1): 265-275.