在强动力荷载作用下结构滞回力可直接描述损伤的发生发展过程,并用于结构耗能的定量评估.提出一种仅利用结构部分自由度上加速度响应时程且结构刚度、阻尼、质量均未知时的结构质量识别迭代和滞回力识别方法.首先基于质量预估值利用扩展卡尔曼滤波方法预测结构的位移和速度响应以及未知加速度响应,利用二重切比雪夫多项式对质量进行更新并迭代直到收敛,最后基于收敛的质量识别值描述结构滞回性能,识别结构滞回力.在一个多自由度集中质量数值模型中引入磁流变阻尼器模拟非线性构件,在结构仅已知部分自由度上加速度响应时程的条件下,数值模拟结果发现结构质量分布和阻尼器的滞回阻尼力均有良好的识别结果,同时考察了测量噪声的影响.%Structural hysteretic force can provide a direct description for the initiation and development of structural damage and can be used for the quantitative structural energy consumption evaluation under dynamic loadings. In this study, a mass distribution and iterative structural hysteretic force identification approach is proposed. Acceleration responses at part of the degrees of freedoms (DOFs) of a nonlinear structure with unknown structure mass, stiffness and damping coefficients are employed for the hysteretic force and mass identification. First of all, the extended Kalman filter (EKF) is employed to forecast structure displacement, velocity in all DOFs and the unmeasured acceleration responses with the assessed mass matrix and the partially measured acceleration response. Then, a double Chebyshev polynomial model is employed to identify the hysteretic force and to update the mass. With the updated mass, the identification approach is repeated until the convergence criterion is met. Finally, a multi-degree-of-freedom (MDOF) structure equipped with a magnetorheological (MR) damper is employed to simulate the non-linear components. Based on the approach, the hysteretic force and mass distribution are identified successfully with partially known noise-polluted acceleration measurements.
展开▼
