Research on Damage Identification Method of Composite Materials Based on Displacement Modal Shape Parameters

[摘要] In terms of dynamic detection, in order to improve the identification effect of model parameters on damage, in this paper, a displacement modal shape processing method based on difference accumulation is proposed, and the calculated result of the accumulated difference is used as a damage characterization parameter. With regards to the damage of composite materials, Camanho-Matthews stiffness degradation criterion is introduced to simulate the stiffness degradation characteristics of four damage forms of composite materials: matrix cracking, matrix extrusion, fiber stretching and fiber compression. Taking the composite cantilever beam as the research object, the numerical simulation shows that the difference accumulation method can simultaneously identify the damage of single damage and multiple damage structures under four damage forms, and it can effectively identify the damage forms and damage locations. Moreover, the damage identification sensitivity of the difference accumulation method gradually increases with the position of the damage approaching the fixed end, which has an advantage for the damage identification of the cantilever beam approaching the fixed end.

[学科分类] 物理（综合）