Plastic behavior of double-layer sandwich beam with foam-filled X-shaped cores

This paper analytically and numerically investigates the plastic behavior of double-layer sandwich beams with foam-filled X-shaped cores (DSBFXs). Accounting for the strength of X-shaped core and metal foam, a yield criterion of double-layer sandwich structure with foam-filled X-shaped cores is established. Analytical solution for large deflection of DSBFXs under lateral loading is developed according to the yield criterion. Finite element analysis is conducted. The analytical results match the finite element results well. In additions, the effects of foam strength, face-sheet thickness and inclination angle of the folded plates on plastic behavior of DSBFXs are discussed. The findings indicate that both load-bearing and energy absorption capacities of DSBFXs significantly increase with the increase of the foam strength, face-sheet thickness and inclination angle of the folded plates, the increment decreases as the foam strength and inclination angle of the folded plates increase. The presented analytical model can be employed to predict the large deflection of the DSBFX.