Associate professor, Technion—Israel Institute of Technology, Department of Mechanical Engineering, Haifa,
A new failure criterion for fiber-reinforced composite materials is proposed and its predictions agree very well with experimental results obtained from testing of angle ply glass/epoxy specimens in tension. The criterion is based on Hill's failure criterion for orthotropic materials and predicts first ply failure of laminae under plane stress conditions. Fiber stress and strength are not included in the criterion. The matrix stresses are calculated by nonlinear analysis, assuming the nonlinearity to be confined to shear behavior. When very large interlaminar stresses develop [such as near edges of (±15°)s specimens], the correlation between experimental results and prediction is not very good. The new criterion fits the present experimental results better than two other criteria, namely the Azzi-Tsai and the Tsai-Wu criteria.
Paper ID: CTR10866J