目前曲率方法主要应用于一维梁结构损伤位置的确定,如模态曲率和柔度曲率,因此本文提出一种适用于二维悬臂挡墙的损伤识别方法——模态平均曲率差法,该方法仅需挡墙完好和损伤状态下前几阶模态振型。首先引入微分几何理论中曲面上一点的平均曲率概念,通过该点上2个主曲率求其平均曲率,利用中心差分法计算挡墙损伤前、后的模态平均曲率值,再利用其差值的绝对值作为损伤识别新指标;然后通过损伤指标识别挡墙的损伤位置,建立损伤位置处的损伤程度和指标值的拟合曲线,进而确定其损伤程度;最后通过悬臂挡墙数值算例,验证不同损伤位置和损伤程度下所提出方法的有效性和敏感性。研究结果表明,模态平均曲率差法的损伤识别精度令人满意。因此,该方法可为挡墙损伤检测提供理论参考依据,并具有工程应用价值。 At present, the curvature method is mainly used to determine the damage location of one-dimensional beam structures, such as modal curvature and flexibility curvature. Therefore, this paper presents a modal mean curvature difference method suitable for two-dimensional cantilever retaining wall damage identification method The method requires only the first few modes of mode shapes in intact and damaged retaining walls. First of all, the concept of average curvature of a point on a curved surface in differential geometry theory is introduced. The mean curvature of the two principal curvatures is calculated by this method. The mean curvature of the modal before and after the retaining wall is calculated by the center difference method. Then the damage location of the retaining wall is identified by the damage index and the fitting curve of the damage degree and the index value at the damage location is established to determine the damage degree. Finally, by numerical example of the cantilever retaining wall, Verify the validity and sensitivity of the proposed method for different damage locations and degrees of damage. The results show that the accuracy of modal mean curvature difference method is satisfactory. Therefore, this method can provide theoretical reference for the damage detection of retaining wall and has engineering application value.