Improved Dynamical Modeling Method for Structure with Small Damage
Yan Yunju,Han Li,Yu Long,Jiang Jiesheng
(Northwestern Polytechnical University, Xi'an, 710072)

Abstract: The existing methods for structural damage indentification, such as GA algorithms and neural networks technology, are usually implemented based on few measured data and a large number of simulation data from structural vibration responses. Construction of an acurate and efficient dynamics model for a structure with different damage becomes an important precondition, thus plentiful simula tion data of structural vibration response can be acquired using the dynamics model of the structure with damage. There are two problems during direct meshings mall structural damage in FEM modeling, i.e., excessive gridding number and unav oidable errors from different meshing for the same damaged structure. To solve t hese two problems, an improved modeling method based on modifying element stiffness matrix at damage position is presented, and corresponding algorithm for dama ged element stiffness matix is adopted. The influence of damage position and con straint conditions on the modification coefficient for small structural damage is simultaneously discussed.
Keywords: small structural damage, FEM mesh, element stiffnes matrix.