Experimental analysis of foam sandwich panels with projection moiré

The use of polymeric and metallic foam sandwich panels in naval, aerospace, railway and automotive constructions is rapidly growing in the recent years because of technological improvements in manufacturing processes. However, it is still difficult to establish a direct relationship between the mechanical properties possessed by the panel and the specific manufacturing process. Mechanisms behind panel deformation, crack growth, fracture initiation and propagation still are not completely understood and therefore are intensively studied. In particular, structural behavior under compression is a critical issue also in view of the lack of official standards on foam core sandwich panels. This work aims at studying mechanical properties of high density polyethylene foam core sandwich panels produced by rotational molding. These panels can be built without using adhesives as the polyethylene foam grows inside mold and then adheres to facesheets while material still is at high temperature. In the present study, polyethylene foam panels of different thickness are tested under edgewise compression loading. The resulting out-of-plane deformation is then monitored in detail with a projection moiré setup including two projectors and one camera.