Flexural property evaluation of web reinforced GFRP-PET foam sandwich panel: Experimental study and numerical simulation

This work focus on the flexural property of polyethylene terephthalate (PET) foam-filled lattice composite sandwich panels subjected to four-point bending (FPB). The effects of different face sheet and core thicknesses on the flexural properties of the sandwich panels were analyzed. Experimental results indicated that the glass fiber-reinforced polymer (GFRP) webs can effectively prevent the sandwiches from catastrophic failure, the failure modes of the structures are dominated by foam shear, top face sheet compressive, and top face sheet-core debonding. Increasing the face sheet and PET foam thickness can effectively improve the ultimate load of the panels by 88.9% and 115.6%, respectively. An analytical model was employed to accurately predict the bending stiffness, ultimate load, and failure modes of the structures. The errors between theoretical predicted and experimental results are within 10% in terms of bending stiffness and ultimate load. Furthermore, a 3D numerical model was built to understand the failure modes and responses of the structures, a continuum damage material model for PET foam was imported into ABAQUS software by VUMAT subroutine, and Hashin failure criterion was used for GFRP. The simulated failure modes and load-displacement curves were in good agreement with experimental results.