Influence of Radial Compressive Stress Owing to Pressure On the Failure Modes of Composite Tube Specimens

Abstract

The failure behaviour of unidirectional laminae in σ₁ - -σ₂ stress space has been studied using thin wall hoop-wound tubular specimens. σ ₁ was generated by internal pressure and -σ₂ by axial compression. It was found that the radial compressive stress -σ ₃, due to internal pressure, has a profound effect on the failure behaviour in the range where failure occurred by matrix fracture. A model is presented for the effect of the radial compressive stress using a matrix failure criterion. The experimental data agreed reasonably well with the predictions of failure stresses based on this model. Optical microscopy revealed that shear deformation preceded final fracture in agreement with the model.