基于模态应变能的不同损伤指标对比

为解决工程结构的多损伤识别问题，对基于模态应变能的不同损伤指标方法进行了对比分析和研究。首先，描述了3种损伤指标，即模态应变能变化指标( MSECI)、模态应变能耗散率指标( MSECRI)和模态应变能基指标( MSEBI)；然后借鉴模态应变能耗散率指标的建立原理，通过对刚度矩阵的修正，建立相应的能量等效方程，并提取了一种模态应变能等效指标( MSEEI )；最后对4种应变能损伤指标进行了对比研究，并考虑了测量噪声的影响。数值仿真结果表明，模态应变能基指标可以较好地识别结构的损伤位置，模态应变能等效指标则不仅可以有效地识别结构的损伤位置，而且可以较为精确地识别结构的损伤程度。

Comparison of different damage indices based on modal strain energy

In order to solve the problem of structural multi-damage identification, different modal strain energy damage index methods are studied and compared. First, three kinds of modal strain energy damage indices, the modal strain energy change index, the modal strain energy dissipation ratio index, and the modal strain energy based index, are described. Then, with consideration of the modal strain energy dissipation ratio index method, an improved equivalence equation is derived through improvement of the stiffness matrix, and a modal strain energy equivalence index is proposed. Finally, four kinds of modal strain energy damage indices are compared, and the impact of the measured noise is considered. Simulation results show that the modal strain energy-based index method can identify structural damage locations, and the proposed modal strain energy equivalence index can not only identify structural damage locations but can identify the damage extent with high accuracy.