Flatwise compression and flexural behavior of foam core and polymer pin-reinforced foam core composite sandwich panels

• New type of sandwich panel was developed.
• The mechanical properties of composite materials were determined experimentally.
• The mechanical performance of sandwich panels was studied and compared.
• The effect of the diameter of polymer pins on mechanical performance was studied.
• The effect of the loading rate on mechanical performance was studied.

The behavior of foam core sandwich (FCS) and polymer pin-reinforced foam core sandwich (PRFCS) panels was experimentally explored for flatwise compression and flexural loadings. The FCS and PRFCS panels were made of chopped strand mat glass/polyester as face sheets and polyurethane foam as core material using a vacuum infusion process. The aim of the study is to determine the effect of the polyester pin reinforcement in the foam core when the panels are subjected to flexural and flatwise compression loadings. Moreover, the effects of different loading rates on the flexural response of glass/polyester laminate and both types of the sandwich panels were determined. It was found that by reinforcing the foam core with cylindrical polymer pins, the flatwise compression and flexural properties of panels were increased significantly. Furthurmore, it was found that the diameter of polymer pins had a large influence while the loading rate had a moderate influence on the flexural stiffness of both types of the composite sandwich panels.