Material characterisation and failure envelope evaluation of filament wound GFRP and CFRP composite tubes

In addition to the basic strength data, the complete failure envelopes in the plane σ2 − τ12 were also evaluated for both materials by the use of the biaxial test procedure here developed. The experimental failure envelopes were also compared with the prediction made with some of the most common failure theories currently available. The results clearly showed the ability of the Puck criterion to accurately predict the failure envelope (especially when torsion plus axial compressive loads were applied to the samples).