通过理论分析证明曲率模态差指标存在两个不足:一是对曲率模态节点处损伤不够敏感,二是不能有效反映损伤程度。对曲率模态差指标进行改进,提出叠加曲率模态改变率指标,理论上克服了原指标的不足。采用连续梁算例进行对比验证,结果表明新指标能够同时反映损伤位置和损伤程度,较曲率模态差指标更加优越。最后提出了基于新指标的单元损伤因子估算方法并验证了有效性。 Theoretical analysis shows that there are two deficiencies of the curvature modal index: one is not sensitive enough to damage at the curvature modal nodes, and the other is that it can not effectively reflect the degree of damage. The modal index of curvature modifier is improved, and the modal change rate index of superimposed curvature is proposed, theoretically overcoming the deficiencies of the original index. The results of continuous beam simulation show that the new index can reflect both the damage location and damage degree, which is more superior than the curvature modal index. Finally, a new index based unit damage factor estimation method is proposed and validated.