Static bending strength assessment of sandwich panels with glass/polypropylene faces and aluminum foam cores

The four-point bending tests were performed first on the sandwich beam with glass/polypropylene faces and aluminum foam cores. The face thickness, core height, and angle-ply directions were considered as the variables to prepare the specimens. The effects of these variables on the bending strengths and the failure modes of the studied sandwich beams were experimentally analyzed using an MTS 810 material testing system and a four-point bending jig. Experimental results show that four failure modes, i.e. face-sheet failure, local indentation, and two types of core shear failure, were observed for the specimens with various experimental variables. The theoretical strengths for the four failure modes were proposed based on the mechanical strengths of the faces and cores. Among the four theoretical strengths, the lowest one is selected as the predicted strength and the corresponding mode is the predicted failure mode. The comparison results between the predicted and experimental strengths and failure modes were provided in the study. Assessment results show that the prediction errors are found to be below 30% for most specimens.