Failure behavior study of repaired bismaleimide resin matrix composite laminates with considering repairing process

Bismaleimide resin (BMPN) matrix composites are widely used in aircraft load-bearing components. Their damage assessment and repair schemes after impact are always the important issues in the research of civil aircraft composite. In order to better understand their failure behaviors, especially after the cementing repair of the composite laminates, a three-dimensional finite element model of the BMPN matrix composite was established. The constitutive models of the 3D Hashin criterion and the B-K criterion were implemented through the ABAQUS subroutine USDFLD to simulate the damage behavior of composite laminates and adhesive layers, respectively. Through the simulation the influences of the layer setting of the patch and the layer property on the strength recovery after the repair process were compared and discussed. The results show that the failure mode of the parent laminate highly depends on the fiber angle, and the recovery effect of the repaired composite laminates can be significantly improved by adding additional layers with the increasing adhesive layer strength.