中文摘要：

从杆的纵向振动方程出发，建立了其相应的有限元动力学方程，利用直接积分法计算了杆在外激励下的振动响应．将杆的局部损伤模拟为单元抗拉刚度的减少，推导了响应对单元抗拉刚度的灵敏度，并利用此响应灵敏度进行杆的局部损伤识别．数值算例表明，该文方法能快速准确地识别出杆的局部损伤，并且对模拟的人工噪声不敏感，说明本文方法具有一定的工程应用前景．

英文摘要：

The dynamic equation of rods for finite element calculation is obtained from the longitudinal vibration analysis of rod. The dynamic response of a rod under external force is calculated from the New- mark direct integration method. The local damage in the rod is simulated by a reduction in the elemental tensile stiffness. The dynamic response sensitivity with respect to the physical parameter （elemental tensile stiffness） is derived. In the inverse analysis, the local damages in the rod are identified from dynamic response sensitivity-based finite element model updating method. It is tounct tlaat the local aamage（s） can be identified successfully from the time histories of several nodes. The effect of artificial measurement noise on the identified results is also discussed. Numerical simulation shows that the proposed method is effective for damage detection and it is insensitive to the artificial measurement noise. Thus it has the potential for practical applications.