Abstract: Based on the basic principle of continuous damage mechanics, a three-dimensional progressive damage model considering shear nonlinearity is established to analyze and predict the mechanical behavior, failure load and failure mechanism of composite laminates. The high-order exponential function is used to describe the shear nonlinear behavior of composite materials. Considering the combination of progressive and sudden reduction of composite stiffness to characterize the stiffness change of materials in the damage process, a UMAT subroutine is compiled, and ABAQUS software is used to analyze the progressive damage failure of perforated AS4/PEEK composite laminates. The model proposed in this paper has higher accuracy than the traditional model simulation results without considering shear nonlinearity, and the error value is less than 4% compared with the reported experiments. The simulation results show that the larger the aperture, the greater the stress limit around the inner hole before the damage occurs, the greater the stress distribution gradient, and the smaller the bearing capacity of the laminated plate. When the [±45]_2S ply is adopted, the simulated stress is in good agreement with the experimental results, which further verifies the applicability and accuracy of the model.

Key words: shear nonlinearity, progressive damage analysis, open-hole laminates, composite, finite element