Matrix Progressive Damage Modeling of CFRP Thin-Walled Connection Hole

Composite thin-walled connection holes exist in large numbers in aircraft structures, but the connection holes are the weak link of the overall structure and are very prone to damage. Unlike metal materials, the failure process of composite connection holes shows obvious characteristics of damage accumulation. Generally speaking, matrix cracks are the first damage mode of composite structures, which is also known as sub-damage, and the structure can still bear the load when the damage occurs, but the structural strength and stiffness will be affected. Therefore, based on the synergistic mechanics damage model, ANSYS finite element analysis software is used to evaluate the gradual damage and stiffness degradation of matrix cracks at the composite connected hole laminate at static low load levels, and reveal the mechanism of structural damage initiation and propagation. This study provides technical guidance for the optimal design of anti-damage connection of aircraft composite materials.