中文摘要：

针对大型土木结构损伤识别优化效率低的问题，提出了子结构虚拟变形方法。虚拟变形方法是一种结构快速重分析的方法，该方法利用单元的虚拟变形模拟结构的损伤，可以在不重新建立有限元模型的情况下，快速计算出结构参数改变后的结构响应。该文基于虚拟变形法的基本思想，对子结构的刚度矩阵进行分解和对损伤后结构运动方程进行整理，推导出利用子结构的虚拟变形刻画损伤的方法，扩展了虚拟变形方法的适用范围；并且给出了虚拟变形和结构响应的相关性计算公式，通过相关性分析提取主要的虚拟变形，减少参与计算的子结构虚拟变形的数目，提高计算效率；最后利用一个五十层框架的数值仿真验证方法的有效性。

英文摘要：

Aiming at the low optimization efficiency of the large structural damage identification in civil engineering, a Substructure Virtual Distortion Method （SVDM） is presented base on Virtual Distortion Method （VDM）. VDM is a fast structural reanalysis method which uses virtual distortions to simulate structural damages, and the modified structural responses can be estimated quickly without rebuilding the whole structural finite element model. Based on the VDM, the way of virtual distortions of the substructure is reduced to simulate its damages through the eigen-decomposition of the substructure stiffness matrix and the analysis of the structural motion equation, and thus it extends the application of the VDM to more complex practical structures. Via analysing the correlations of the distortions with structural responses, the main virtual distortions of the substructure are picked up to reflect the damages. The correlation estimation equation is presented. This reduces the number of necessarily-considered virtual distortions and increases the computational efficiency. A numerical 50-story frame model is used to verify the proposed method.