On the crushing response of composite sandwich panels subjected to edgewise compression: experimental

In the present work the compressive properties, collapse modes and crushing characteristics of various types of composite sandwich panels were investigated in a series of edgewise compression tests. The tested sandwich panels were constructed trying four types of polymer foam core (more specifically PMI foam, two grades of linear PVC foam and polyurethane foam) and two types of FRP faceplate laminates made of glass fibre reinforcements impregnated in modified acrylic resin in eight different material combinations. Three modes of collapse were recorded in the compressive tests, one of which being progressive end-crushing of the sandwich panel featured by significant crash energy absorption, feature that was a highly desired since the tested hybrid composites were candidate materials for the manufacture of parts of transportation vehicles. The influence of the most important material properties of the faceplate laminates and foam core and the sandwich construction geometry on the compressive response and the crushing characteristics of the tested sandwich panels such as the peak load, crash energy absorption and collapse modes is extensively examined and analysed. Particular attention is paid on the analysis of the mechanics of progressive deformation and crumpling of the sandwich panels in each of the three collapse modes and especially of the end-crushing mode, emphasizing on the mechanisms related to the crash energy absorption during the edgewise compression of the sandwich panels.