The effect of core configurations on the energy-absorbing behaviour of all-composite sandwich structures

This paper presents the energy absorption characteristics of all-composite sandwich structures filled with PVC foam subjected to quasi-static and dynamic loading. Compression and drop-weight impact tests have been undertaken to evaluate the mechanical response of sandwich structures made with glass fibre/epoxy (GFRP) and carbon fibre/epoxy (CFRP) corrugation cores embedded with PVC foams. The corrugation core thicknesses are in a range from 0.25 to 1.25 mm, whilst the PVC foams are of a density of 40, 80 and 130 kg/m³, respectively. The energy-absorbing capability is evaluated by determining the specific energy absorption (SEA) of each configuration. The mechanical response of the sandwich structures is also modelled using the finite element method, which is validated against the corresponding experimental data. The relationship between the density of PVC foam and the thickness of corrugation composite is explored via a two-way analysis of variance. The results show that both thick corrugated core and high-density foam contribute to the increase of the compressive strength and specific energy absorption of the structure. However, the structure with the optimal performance is not the structure with the thickest corrugation core and the highest foam density. In contrast, C130 foam-filled CFRP corrugation core with a thickness of 0.75 mm is the most attractive option in terms of specific energy absorption and compression strength.