【摘要】 对橡胶隔震结构的在线损伤识别进行了实验研究。建立橡胶隔震结构实验模型,对其进行振动台实验。采用一套刚度元件装置(SED)在线实现结构的层间刚度突变,模拟结构损伤。对结构施加不同地震波基础激励,测量结构各层的加速度响应和基础加速度信号,提出自适应序贯非线性最小二乘(adaptive sequential nonlinear least square estimation,简称ASNLSE)方法,基于测得的加速度信号对橡胶隔震结构的参数及其变化和隔震结构各层位移进行在线识别,判断结构损伤的位置和程度。实验结果表明,ASNLSE方法能够准确识别橡胶隔震结构的参数,并追踪结构参数的变化,且识别的位移与实测位移曲线吻合良好,验证了该方法在基础隔震结构损伤识别中的有效性和准确性,具有实际应用价值。更多还原

【Abstract】 The experimental studies are performed and presented to verify the capability of the adaptive sequential nonlinear least square estimation (ASNLSE) approach for identifying and tracking damages in nonlinear structures. A base-isolated building model, consisting of a scaled shear-beam type building model mounted on a rubber-bearing isolation system, has been tested experimentally in the laboratory. The classic Bouc-Wen model is adopted to describe the nonlinear behavior of the rubber-bearings, and the acceleration and the displacement responses are measured during the tests. To simulate structural damages during the test, the stiffness element device (SED) is adopted herein to reduce the stiffness of the upper story of the model abruptly. Two earthquake excitations have been used to drive the test model, including the El Centro and Kobe earthquakes. Various damage scenarios have been simulated and tested. Measured acceleration response data and the ASNLSE approach are used to track the variations of stiffness during the test. The tracking results for the stiffness variations agree well with that predicted by the finite-element method and the predicted displacements also match well with the experimental data. It is concluded that the ASNLSE approach is capable of tracking the variations of hysteretic structural parameters leading to the detection of structural damages, and has a practical application value.更多还原