基于模态柔度矩阵识别结构损伤方法研究

Research on the Method of Structural Damage Detection Based on Modal Flexibility Matrix

基于模态柔度对结构损伤的高灵敏性,采用低阶的模态参数,利用结构损伤前、后的模态柔度矩阵,计算出模态柔度改变率,并对其进行中心差分,得到模态柔度改变率曲率,作为结构损伤识别的新指标.以简支梁和四跨连续梁为例,建立有限元模型,考虑多种损伤情况,计算新指标,并与模态柔度差、模态柔度改变率、模态柔度差曲率等指标进行对比分析,证明了新指标的有效性和简便实用性.

Based on the high sensitivity of the change in modal flexibility to structural damage, the rate of modal flexibility curvature is presented as a new indicator for structural damage detection, derived from rate of modal flexibility calculated before damage and after damage by means of difference calculation through only a few of the lower order modes. The simply supported beam and four - span continuous beam are taken as the numerical simulation examples with considering the single damage and multiple ones. Comparing with the modal flexibility, rate of modal flexibility and curvature of modal flexibility, the results show that the new indicator is more effective and practical.