Interlaminar Stress and Strain Energy Release Rate Predictions in Composites bySingular Fitting

摘要

A singular fitting method is developed in order to predict the interlaminarstress distribution in a quasi-isotropic double cracked-lap-shear configuration made of graphite/epoxy material. The method is based on an improved finite element scheme using the stress predicted by a constant strain element. The oscillatory component of the stress singularity is investigated, and the order of the-singularity is estimated from a logarithmic plot of interlaminar shear stress data. The effect of the mesh size on the stress and displacement distributions is isolated. The strain energy release rate components are predicted based on the singular stress distribution and its associated displacement field. The effect of smearing the material properties on the accuracy of the strain energy release rates and interlaminar stresses is investigated. Results are compared with the finite element crack-closure method. A comparison of the stress-intensity factor with an analytical solution is provided. Composite materials, Interlaminar fracture, Strain energy release rate, Crack-closure method, Finite element method, Fracture mechanics, Fatigue(Materials).