未知外部荷载下结构的在线损伤诊断

On-line Damage Detection Under Unknown External Loadings

结构在线损伤诊断是目前土木工程界关注的热点问题之一.针对该问题进行研究,根据部分观测的结构加速度响应信号,基于扩展卡尔曼预测和优化函数对结构进行在线的物理参数识别及结构刚度突变的追踪,同时利用最小二乘识别未知外部荷载.数值算例表明,本文提出的算法能够较准确地识别系统参数和未知外部荷载,并且判断结构刚度损伤发生的时刻、位置和程度,且具有一定的抗噪性.

In present,on-line structural damage detection attracts much focuses in the field of civil engineering.Extended Kalman estimator and optimal function were adopted for estimating the structural parameters and tracking the abrupt degradation of structural stiffness based on the partial accelerations,and the unknown external loading can be calculated in the same time through least squares estimation.Numerical example indicated that the proposed algorithm can estimate the system parameters and the unknown external loading precisely,and track the exact moment,locations and extents of structural stiffness degradation on-line effectively using the partial observations of structural acceleration responses polluted by measurement noise.