Application study on parametric estimation of rubber bearings using SNLSE approach
YIN Qiang; ZHOU Li; WANG Xin-ming
(MOE Key Lab of Structure Mechanics and Control for Aircraft; Institute of Structures & Strength; Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China)
应用简化的Wen模型分析橡胶隔震支座的非线性动力行为，并用试验方法测试得到GZN110型橡胶支座的相关力学参数。通过引入Newmark-β状态转换和分步求解未知参数的方法，使得序贯非线性最小二乘方法(SNLSE)只需测量加速度和激励信号就可以一次辨识模型的所有参数。该方法具有输入量少、计算精度高、易于实现的优点。以GZN110型橡胶支座为实例进行了白噪声、El Centro 地震波以及Kobe地震波激励的仿真和实验研究，结果表明，这种简化的Wen模型能较精确地模拟隔震支座的动态力学行为，应用序贯非线性最小二乘方法得到的隔震支座模型参数与实际值较吻合，而且隔震支座位移的辨识结果与实测值相当一致，证明该方法在橡胶隔震支座检测和状态评估中的有效性和精确性。
Abstract：Because of the complex nature of the excitation and the inherent non-linear dynamics characteristics of base isolation system, the prediction of the dynamic response of rubber-bearings subjected to strong earthquake is quite challenging. A simplified Wen model was proposed to describe the non-linear behavior of rubber bearings. Experimental tests using a particular type of rubber-bearing (GZN110) had been conducted to identify the parameters of the proposed hysteretic model. Based on experimental vibration data measured from sensors, a new system identification method, referred to as the sequential non-linear least-square estimation (SNLSE), was used to identify model parameters. The SNLSE approach has significant advantages over extended Kalman filter (EKF) approach in terms of stability and convergence of solutions as well as the computational efforts involved. Different excitation scenarios, including white noise and several earthquake, Signals were enoliyed as input signals in simulations and experimental tests. Those results demonstrate that the simplified Wen model is capable of well describing the non-linear behavior of rubber-bearings, and the SNLSE approach is quite effective for identifying non-linear hysteretic parameters and for the prediction of displacement.
2010, Vol. 29 
