Influence of skin wrinkles and resin insertions in maximum stress of transitions of pure bending sandwich beams

Abstract The sandwich beam has emerged as a part of new engineering applications in recent years. Dimensional and mechanical control tests are used to avoid possible service failures. Sandwich beams are modeled as large deflection pure bending beams with monolithic ends. The manufacturing process of sandwich beams can lead to different dimensional and shape defects such as wrinkles in traction and compression skins, insertions of epoxy resin in foam core or in the skins, shape defects of the foam, etc. In order to study the maximum stress behavior of beams with different types of defects, a specific finite element model (FEM) has been developed. Finally, the results of FEM analysis are validated using experimental tests. The implications of these findings on the structural integrity of glass-fiber-reinforced polymer (GFRP)-foam sandwich composites are discussed.