基于静力虚拟变形法的结构损伤识别研究
Study on Structural Damage Identification by Static Virtual Distortion Method

为了提高大型结构损伤识别的计算效率，引入静力虚拟变形法（VDM），并结合序列二次规划（SQP）算法实现损伤定位和损伤定量。首先，基于VDM的基本原理，推导了损伤因子与虚拟变形的关系；其次，建立损伤应变与实际损伤应变的目标函数，并利用SQP算法优化目标函数，实现了结构损伤识别的快速计算；最后，以某实际大桥有限元模型为例，对其吊杆的损伤识别进行了数值模拟研究。设计了基于恒荷载的实时监测和基于车辆静荷载的定期检测2种工况对该方法进行验证。结果表明：该方法能够快速准确地识别出损伤发生的位置和程度。
In order to improve the computing efficiency of large structure damage identification, the static virtual distortion method (VDM) was introduced and coupled with the sequential quadratic programming (SQP) algorithm to realize the damage localization and damage quantification. Firstly, based on the basic principle of VDM, the relationship between the damage factor and the virtual distortion was deduced. Secondly, SQP algorithm was used to optimize the objective function which was established by damage strain and actual damage strain, and the fast computation of structural damage identification was realized. Finally, a finite element model of actual bridge was taken as example, and the damage identification of suspenders were studied by the numerical simulation. Two conditions of real time monitoring based on constant load and periodical detection based on vehicle static load were designed to verify the proposed method. The results show that the proposed method can rapidly and accurately identify the damage location and degree