Damage Progression in Laminates under In-plane and Edge Moment Loads
Abstract
Damage progression in laminates with in-plane loads and edge moments is investigated herein analytically. Simple-supported laminated composite columns subjected to off-center compressive loads are analyzed. They undergo large displacement while strains remain small when subjected to off-center compressive load. The damage initiates before the column buckles. The stress gradients appear along the length of the column because of the large displacement. Wolfe used these columns in experimental study of damage progression in a gradient stress field. The same composite laminate column geometry and lay-ups are analyzed using the finite element method which incorporates the two phases continuum damage model. The geometric nonlinearity due to large displacements is implemented in an approximate way in the finite element procedure. The damage initiation load predictions compare favourably with the experimental results. The prediction of plies and the planer location with in the ply where damage initiates also matches with the experimental observations.