An adaptive integration scheme for efficient fracture analysis using cohesive zone model

• Effects of integration schemes are thoroughly examined for fracture analysis using cohesive zone models. • Numerical accuracy and efficiency are enhanced by integration schemes with multiple integration points. • An adaptive integration scheme is proposed to optimize the number of integration points based on the state of the element. Cohesive zone models are widely used in fracture analysis of composites due to their effectiveness in modeling damage evolution. However, coarse cohesive elements (CEs) often struggle to capture the high-stress gradients within the cohesive zone, necessitating a fine mesh to achieve accurate results, which substantially increases computational costs. This study examines the impact of integration schemes on the numerical performance of CEs. A multi-point integration scheme is shown to enhance the stress-capturing capability compared to the standard 2 × 2 integration scheme, while reducing iteration counts and improving computational efficiency. Notably, the computational gains achieved by optimizing integration points can outweigh the additional cost of increased points. Based on these findings, an adaptive integration scheme is proposed: standard 2 × 2 integration is employed for CEs in the elastic and fully fractured phases, while integration points are refined near and within the cohesive zone to optimize the computational effort. Numerical results demonstrate that the proposed adaptive scheme significantly reduces numerical iterations and improves computational efficiency in the fracture analysis of composite materials.