Numerical simulation and experiment validation of variable stiffness composite laminates with open holes under unidirectional tension

Curvilinear fiber format is one of the effective ways to improve the mechanical properties of composite components.The laying trajectories of open-hole composite laminates were investigated. B-spline interpolation was used to obtain the laying trajectory of open-hole composite laminates with the maximum principal stress. The variable stiffness open-hole composite laminate model was established by discrete grid method.The tensile failure numerical simulation and damage failure analysis were carried out by Tsai-Wu damage failure criterion and constant stiffness degradation criterion. Two sets of constant stiffness and variable stiffness open-hole composite laminates experimental specimens were placed, respectively. A tensile strength experiment was performed.The results show that the numerical simulation accurately captures the data from experiment. The tensile strength of variable stiffness open-hole composite laminates, compared with constant stiffness open-hole composite laminates, increases by 26.92%, and the damage evolution processes of both are significantly different.