The effect of free edges on inter-laminar performance of curved laminates

Abstract

A method for an assessment of the edge effect in curved laminates under four-point bend test is presented. The methodology uses ABAQUS FE analysis and the results are compared to the test results. FE analysis suggests that increase in strength from curved laminated with free edges to equivalent infinitely wide laminates can be as significant as 60%-120%. A way of reducing the edge effect by applying a thick layer of resin to the free edges is investigated using the developed methodology and compared against test results. Up to 19% increase in strength of curved elements with edge treatment has been confirmed in tests. Detailed FE analysis suggests that even greater edge effect mitigation, and therefore further increase in element strength, can be achieved if the contrast between the properties of the inter-laminar material and the resin used in edge treatment becomes smaller.