Strain-based theoretical fatigue damage model of woven glass-epoxy fabric composite material

Abstract

Strain-based theoretical fatigue damage model is developed by utilizing internal variable theory of thermodynamics of continuum damage mechanics approach related to woven glass fabric composite material. Based on the laminate theory of composite engineering, a phenomenological fatigue damage model under decomposition of Helmholtz Free Energy (HFE) is carried out to demonstrate the stiffness degradation, decrease in the Young's modulus of elasticity), damage development corresponding to normalized life, its accumulation, strain evolution, loss in strength and stress reduction. Investigational data from the tensile fatigue test from different literatures were employed to verify the model and the results show that model can describe strain-based theoretical fatigue damage of woven glass fabric epoxy composite material.

Keywords

• Woven glass–epoxy composite
• Internal variable theory of thermodynamics
• Accumulative damage
• Strain-based
• Normalized cycles
• Damage model