Crushing behavior and energy absorption of steel-GFRP-foam sandwich structures under quasi-static compression: Experimental and theoretical study

Abstract

To overcome the poor energy-absorbing efficiency of existing layered panels, three kinds of novel steel-glass fiber reinforced polymer (GFRP)-foam sandwich structures composed of two steel face sheets and GFRP-foam composite cores were proposed in this paper. The effect of the composite core thickness and GFRP lattice configuration on the energy absorption performance for sandwich structures was studied through quasi-static crushing tests. Considering the role of steel face sheets, a theoretical prediction model was derived to calculate the initial absorbed energy for all types of sandwich panels. Parametric studies were carried out to investigate the influence of five different variables (axial compressive load, steel sheet thickness, GFRP web thickness, GFRP and foam compressive modulus) on the overall energy dissipation for each kind of composite panel. Test results indicated that both the thicker core component and double-layered dislocation GFRP layout could effectively promote the energy consumption property of all the steel-GFRP-foam structures, and the steel face sheet played a crucial role in the proposed sandwich panels due to its excellent absorbed-energy capacity per volume and exceptional ductility. Theoretical results demonstrated that the equivalent energy-absorbing formula was desirable to be used to assess the crushing resistant behavior of each sandwich structure. Parametric analysis results showed that a larger axial compressive load was able to improve the structural initial energy absorption, but the increase of four other structural parameters, especially the thickness of the front (rear) steel sheet, could weaken such an identical performance.