On State of Damage and Plasticity in pressurized layered Composite Tubes

Abstract

A method has been developed for the prediction of successive failure due to transverse cracking in wound composite layers and plastic deformation in isotropic layers of thick walled layered composite tubes. The model can be used for solving cases of axisymmetric loads and balanced laminates, and variation of material properties through the thickness can easily be included. The method is based on incremental loading and successive elastic solutions where transverse cracking and yielding are predicted simultaneously. The effective elastic parameters and the stress and strain field in the cracked composite layers were obtained from an approximate analytical model in closed form. This model is based on a proposed displacement field and was solved by variational principles. A method was also developed for the prediction of plastic yielding in isotropic layers. This was based on wellknown theory.