STRESS AND FAILURE ANALYSIS OF REPAIRED SANDWICH COMPOSITE BEAMS USING A COHESIVE DAMAGE MODEL

摘要

The behaviour of a repaired sandwich beam subjected to four point bending is investigated numerically using the ABAQUS~R software and special developed interface elements including a cohesive mixed-mode damage model based on the indirect use of Fracture Mechanics. The two major repair configurations for sandwich structures namely overlap and scarf repair, are studied. The interface elements placed at the middle of the adhesive, parent laminate/adhesive and adhesive/patch interfaces allow to obtain stress distributions at these locations as well as to simulate damage onset and growth. The influence of several geometrical parameters, such as overlap length and patch thickness, in the case of overlap repair, and scarf angle, in the case of scarf repair, is evaluated in terms of stress analysis and strength predictions. Conclusions were drawn about design guidelines of the sandwich composite repair.