基于模态应变能耗散率理论的结构损伤识别方法

STRUCTURAL DAMAGE DETECTION METHOD BASED ON THE THEORY OF DISSIPATIONRATIO OF MODAL STRAIN ENERGY

本文提出了基于模态应变能耗散率理论的一种新的结构损伤识别方法。表示结构损伤的损伤变量的概念来自于材料领域 ,并推广到了构件和结构 ;在此基础上 ,结构单元的损伤变量是通过建立模态应变能耗散率和相应的结构损伤前后的应变能变化的关系而获得。该方法所要求的结构损伤前后的振型模态可以是不完备的。对测量噪声的影响具有较强的鲁棒性。最后 ,通过数值算例的分析结果说明 ,该方法简便、有效 ,可定位结构的损伤和识别损伤的程度。

A new model_based method for structural damage detection,which is based on the theory of dissipation ratio of modal strain energy,is put forward.The concept of damage variable is extended from material to member and structure.The valid elastic modulus of structure is used to describe the damage extent of each structural element.According to the change of modal strain energy in each element before and after the occurrence of damage,the damage index is obtained.Only incomplete measured mode shapes and analytical system matrices are required in this damage localization and quantification approach.The proposed method in the paper is applied to locate structural damage and furthermore,to determine the damage extent.Numerical analysis shows the method has the capability to successfully detect the damage of structures.