Analysis of high stress gradients in composite plates with rapidly varying thickness

Abstract This is a study of the influence of a rapid variation in thickness in a glass/epoxy composite plate under pure bending load. The plate has two areas of constant thickness connected by two others with varying thickness. Thickness variation is obtained by means of extra layers. Two stacking-sequence modes were studied and a finite-element model is developed which gives the global behaviour of the sample and the local stress concentration near the thickness variation areas. To validate this model and to study the different kinds of failure experimental tests were performed. A pure bending load was obtained with a test machine entirely designed in the laboratory and adapted for flexible structures. Good correlation between experimental and numerical results was obtained.