基于响应灵敏度分析利用车－桥耦合系统的加速度响应进行桥梁结构的局部损伤和车辆参数识别。在正问题中建立了连续桥梁结构和车辆耦合系统的有限元模型，利用 Newmark 直接积分法求出在移动车载作用下系统的动态响应，并进一步推导出动态响应对系统物理参数的时域响应灵敏度。在反问题中利用该响应灵敏度矩阵进行系统的有限元模型修正，识别出桥梁的局部损伤和车辆参数，讨论了人工噪声对识别结果的影响。算例表明该方法具有精度高、对测量噪声不敏感等特点。%Here,both local damages in a bridge's deck and parameters of moving vehicles were identified with a bridge-vehicle coupled system's dynamic responses induced by vehicles moving on the top of the bridge deck.The local damage is simulated by a reduction in the elemental flexural rigidity of the beam.The dynamic model of the bridge-vehicle coupled system was established using the finite element method and the dynamic responses of the system were obtained using Newmark direct integration method.In the inverse analysis,a dynamic response sensitivity-based finite element model updating approach was used to identify both local damages of the bridge deck in element level and parameters of vehicles.The solution was obtained iteratively with the penalty function method and the regularization from the measured structural dynamic responses.A multi-span continuous beam was studied as an numerical example to illustrate the correctness and efficiency of the proposed method.The effects of measurement noise,and measurement time duration on the identification results were investigated.The results indicated that the proposed method is efficient and robust for both damage identification and vehicular parametric identification;good identified results can be obtained with time histories of several measurement points.
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