Failure Modes of Angle Ply Laminates

Experimental investigation of failure of balanced angle-ply laminates under symmetric uniaxial tension revealed three distinct failure modes. The three different modes were observed for reinforcement angles smaller than ±45°, for the ±45° angle ply and for angles larger than ±45°. Comparison of experimental failure loads with theoretical failure loads based on first laminate failure criteria showed good agreement for certain ranges of reinforcement angle and disagreement for others.