摘要
结构非线性恢复力与位移的关系即滞回特性是强动力荷载作用下结构损伤发生发展过程的直接表征,可直接用于结构耗能的定量评估。该文提出一种仅部分自由度受到激励且只有部分自由度上加速度响应测量已知时结构非线性恢复力和质量识别方法。无需结构恢复力参数化模型,利用切比雪夫多项式来描述非线性恢复力,结合无迹卡尔曼滤波算法(Unscented Kalman Filter,UKF),在结构刚度、阻尼、质量未知情况下,实现非线性恢复力和结构质量识别。在一个多自由度数值模型中引入磁流变阻尼器模拟非线性构件,通过数值模拟验证该方法的识别效果。结果表明,该方法在仅部分自由度受激励且仅部分自由度上加速度响应时程已知时,可对结构非线性恢复力和质量进行有效识别。该方法对工程结构在强动力荷载作用下损伤发展过程的识别及耗能的定量评估具有重要意义。
Structural nonlinear restoring force or hysteretic behavior provides a direct description of the initiation and development of structural damage and can be used for the quantitative evaluation of structural energy consumption under dynamic loading. In this study, an approach for identifying nonlinear restoring force and mass distribution using limited acceleration measurements under incomplete excitation condition is proposed. A multi-degree-of-freedom (MDOF) structural equipped with a Magnetorheological (MR) damper mimicking a nonlinear member is established to numerically validate the approach. Based on an Unscented Kalman Filter (UKF) and a Chebyshev polynomial model, without the use of any parametric models of the nonlinear restoring force, or assumption on the stiffness, damping and mass distribution, the nonlinear restoring force and mass distribution are identified successfully. The results show that the proposed time domain nonlinear restoring force identification approach is general and capable of identifying structural nonlinearity and mass distribution with limited acceleration measurements under incomplete excitation cases, which can be used for the damage detection and energy consumption evaluation of engineering structures under strong dynamic loading.
出处
《工程力学》
EI
CSCD
北大核心
2018年第2期180-187,共8页
Engineering Mechanics
基金
国家自然科学基金项目(50978092)