Research on damage identification method of composite laminates based on unit-level damage index by step regularization
For the damage identification problem of composite plywood structure,the traditional damage identi-fication indexes are too rough in describing its damage,and the number of material-level damage parameters is huge and difficult to identify,so the unit-level damage index is introduced,which can reflect the in-plane and out-of-plane damages of the plywood.In order to improve the efficiency of damage identification,a two-step regularized damage identification method for unit-level damage indicators is proposed.Through the progressive failure analysis of composite laminated plate structure,the unit-level damage index is equivalent to the material-level damage index based on stiffness degradation,and the unit-level damage index based on combined stiffness coefficient is constructed,and its correlation is analyzed,which provides prior information for subsequent damage identification.Then the damage parameters are quantitatively analyzed by step-by-step regularization,that is,the first step pro-vides preliminary damage identification results by using the prior information provided by L2 regularization and cor-relation,and the second step solves for the damage variables using the L1 regularization method based on the first step to obtain finer identification results.Numerical simulation and experimental results show that the proposed step-by-step regularization method can effectively realize the damage identification of composite laminates,and the effects of noise pollution and modal order on the identification results are also explored.
indicators of damageregularizationdamage identificationcomposite laminates
万方数据
维普
