Interface fracture of hybrid joint of glass- steel-fiber composite

Purpose - In order to connect a fiberglass composite structure to a steel structure, a hybrid composite made of glass and steel fibers has been studied. The hybrid composite has one end section with all glass fibers and the opposite end section with all steel fibers. As a result, it contains a transition section in the middle of the hybrid composite changing from glass fibers to steel fibers. The purpose of this paper is to examine interface strength at the glass to steel fiber transition section, in order to evaluate the effectiveness of the hybrid composite as a joining technique between a polymer composite structure and a metallic structure.Design methodology approach - The present micromechanical study considers two types of glass to steel fiber joints: butt and overlap joints. For the butt joint, the end shape of the steel fiber is also modified to determine its effect on interface strength. The interface strength is predicted numerically based on the virtual crack closure technique to determine which joint is the strongest under various loading conditions such as tension, shear and bending. Numerical models include resin layers discretely. A virtual crack is considered inside the resin, at the resin glass-layer interface, and at the resin steel-layer interface. The crack is located at the critical regions of the joints.Findings - Overall, the butt joint is stronger than the overlap joint regardless of loading types and directions. Furthermore, modification of an end shape of the middle fiber layers in the butt joint shifts the critical failure location.Originality value - The paper describes one of a few studies which investigated the interface strength of the hybrid joint made of fiberglass and steel-fiber composites. This joint is important to connect a polymeric composite structure to a metallic structure without using conventional mechanical joints.