Progressive failure analysis of perforated composite laminates considering nonlinear shear effect.

Area of Science:

• Materials Science
• Mechanical Engineering
• Computational Mechanics

Background:

• Composite materials offer superior performance for high-stress applications like aerospace.
• Real-world composite structures frequently incorporate features such as notches and voids, necessitating detailed failure analysis.
• Understanding failure evolution in perforated composites is crucial for ensuring the integrity and safety of engineering structures.

Purpose of the Study:

• To numerically simulate the failure evolution and identify failure modes in carbon fiber reinforced resin composite laminates with large openings.
• To develop and validate a robust finite element model capable of predicting progressive damage in composites.
• To investigate the influence of nonlinear shear effects on failure behavior across different laminate stacking sequences.

Main Methods:

• Development of a UMAT subroutine integrating the 3D Hashin-Ye failure criterion and progressive damage mechanics.
• Incorporation of characteristic length and viscosity coefficient to mitigate mesh dependency and enhance computational convergence.
• Integration of the Ramberg-Osgood equation for nonlinear shear constitutive relationships within the damage degradation model.

Main Results:

• The developed model successfully simulates the failure evolution and modes of composite laminates with large openings.
• The introduction of nonlinear shear effects demonstrably impacts the failure progression in laminates.
• Mesh dependency was reduced, and computational convergence was improved through model enhancements.

Conclusions:

• The finite element simulation provides significant insights into the failure mechanisms of perforated composite structures.
• The validated model serves as a valuable tool for predicting the structural integrity of composite components in demanding applications.
• Further research can explore the application of this model to more complex composite geometries and loading conditions.