Investigation of Load Bearing Behavior in Composite Sandwich 3PB Beams with Elastomeric Foam Core

In this paper, the behavior of sandwich beams consisted of GFRP composite laminates as top and bottom skins and an elastomeric foam core from a PE-EVA blend was studied in terms of load bearing capacity and ultimate state of strength. In the experimental program, the sandwich beams were tested in three point bending conditions. Then, FE models according to experimental specimens were investigated considering the nonlinear behavior of structure which originates from hyperelastic performance of the foam core and the damage detection in composite faces. In this way, the ultimate strength of the sandwich beams were determined and compared for FE and experimental models. The results indicate that ultimate strength of the sandwich beams is determined based on the strength of the composite faces without any damage observation in relation with the foam core such as face/core deboning and/or core shear crushing. ìABAQUSî program was utilized for FE simulation of the sandwich structure and 3D solid elements were used for meshing of foam core while the composite faces were selected 2D elements. The results show that sandwich beam with elastomeric foam core rather than rigid foam cores display a unique behavior in large deformations without failure detection along the service life.