摘要:从弦强迫振动方程出发,建立了其相应的有限元运动方程,利用直接积分法计算了弦在外激励下的响应。将弦的局部损伤模拟为单元面积的减少,推导了响应对弦单元面积的灵敏度。并利用此响应灵敏度进行弦的局部损伤识别。数值算例表明,本文方法能快速准确地识别出弦的局部损伤,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实用前景。
Abstract: In this paper, finite element analysis is used for the forced vibration analysis of the string structure. The dynamic response sensitivity with respect to the physical parameter (elemental cross-sectional area) is then derived. In the inverse analysis, the local damages in the string are identified from dynamic response sensitivity-based finite element model updating method. It is found that the local damage(s) can be identified successfully from several dynamic response measurements. The effect of artificial measurement noise on the identified results is also discussed. Numerical simulation shows that the proposed method is insensitive to the measurement noise and with very good accuracy. And it has the potential for practical application.