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提出了一种利用桥梁结构在车辆荷载作用下在线响应评估结构性损伤的方法。以单元弯曲刚度的变化量为识别指标,基于车桥动力相互作用理论计算车激桥梁响应以及响应对损伤指数的灵敏度,以结构不同状态下的响应残差为约束条件,利用最小二乘法求解灵敏度方程得到各单元的损伤指数,然后通过有限元更新技术和反复迭代,最终实现对桥梁损伤的定位和定量分析。分析了测量噪声和轨道不平顺对损伤识别结果的影响规律。数值算例表明,所提的损伤识别方法对轨道不平顺和量测噪声不敏感,可以利用加速度、速度或者位移响应有效识别桥梁的绝对损伤或相对损伤。
A new method to evaluate the structural damage of bridge structure is presented based on the online response of the bridge structure under vehicle load. Based on the theory of bridge dynamic interaction, the response of the bridge and the sensitivity of the response to the damage index were calculated. The response residuals under different states of the structure were used as constraints. The least square method was used to solve the sensitivity The damage index of each element is obtained by the equation, and then the finite element updating technique and iterative iteration are used to finally locate and quantitatively analyze the damage of the bridge. The influence of measurement noise and track irregularity on the damage identification results is analyzed. The numerical examples show that the proposed method is not sensitive to track irregularity and measurement noise, and can effectively identify the absolute or relative damage of bridge with acceleration, velocity or displacement response.