Damage Mechanics in G/E Tubes under Tension-Torsion Cyclic Loading

Abstract

In this work, multiaxial fatigue tests results on [0F/90U,3/0F] glass/epoxy tubes are discussed. Specimens are subjected to combined tension-torsion loadings, resulting in the stress components σ2 andτ12 in the 90° layers of the tubes. The effect of shear stress on damage mechanics has been investigated and a strong influence on both damage onset and propagation has been observed. SEM investigation of fracture surfaces shows the dependence of damage modes, at the microscopic scale, on the multiaxiality condition. Comparison with previous results on tubes with different lay-ups ([904], [0F/90U,3]) shows the strong influence of the constraining 0° fabric layers on the damage onset and propagation.