Modelling electromechanical coupling in woven composites exhibiting damage

Abstract

Electroelastic woven composites are modelled with a transformation field analysis to determine the overall mechanical and electrical responses taking into consideration the progression of internal damage. The solution is found for a representative volume element of the composite material in terms of constant stress concentration factors, which quantify the local stresses caused by overall mechanical loads, and constant influence functions, which quantify the effect of local stress transformations such as those caused by electric fields. The effect of damage in limiting or eliminating local stresses is determined in terms of auxiliary transformation stresses. An example for a three-dimensional woven composite with piezoelectric filaments in the warp fibre direction shows that the computed electric displacement deviates from linearity with applied load at the onset of local damage. The indication of damage through electric displacement is more detectable when loading and electric measurement directions are not aligned. Local damage mechanisms show different effects on the magnitude of electric displacement. Damage within fibre bundles in the warp, weft, and z directions by sliding or splitting has the most significant effect on the electric displacement.