ANISOTROPIC THOERIES AND EXPERIMENTAL STUDIES OF DAMAGE IN LAMINATED COMPOSITES-Ⅱ

The application of the anisolropic damage mechanics to composites is explore in this paper.The outline of the damage tests for laminated composites and some measurement methods are briefly presented.The experimental results of three kinds of laminates under uniaxial tension show the damage energy release rate under uniaxial tension,Y₂,based on Lemaitre's hypothesis of strain equivalence can be used to describe the mechanical state of damaged laminates.The damage evolution law can be represented by the simple function form of Y₂=α(σ/σ_c)^β,where α and β are coefficients which are inedpendent of the shape and size of the initial defect in laminates and can be experimentally determined.The critical damage energy release rate under uniaxial tension,Y_2c,represents the capscity against the damage evolution in the laminates and it is independent o:the shape and sizc of initial defects in laminates.