基于转角模态曲率的损伤识别研究

Research on the Damage Identification Based on Rotational Mode Shape Curvature

摘要:

利用测量得到的模态参数,应用中心差分法求取振型曲率,用损伤前后同一位置的振型曲率变化作为结构损伤的识别指标。采用有限元方法,通过数值仿真,对不同位置发生损伤前后的悬臂梁进行仿真计算,得到其模态参数。利用构造的损伤识别指标对结构损伤情况进行识别研究。在前人研究的基础上,特别提出了利用角位移模态曲率变化来识别损伤位置。仿真算例表明:利用角位移模态曲率比平动位移模态曲率识别损伤的效果更好,精度更高。

Abstract:

The mode shape curvatures were obtained by the central difference method after the mode data was measured in frequency domain. The modal parameters were calculated of a cantilever beam before or after damages occur at different positions by FEM numerical simulation. The given evaluation index was used to identify the damage in the beam. A detection method using the curvature of rotational mode displacement was set forth. The simulating results showed that the damage identification accuracy was better than the used method by translation modes.