Failure Modes of Foam Core Sandwich Beams under Static and Impact Loads

In recent times, sandwich structures have been widely used in load bearing structures due to their high specific stiffness and high specific strength. Some sandwich structures, such as those used in high speed transportations, are required to have high impact energy absorption characteristics also. Since sandwich structures can fail in various modes, in this article, the static failure modes and load capabilities of foam core composite sandwich beams composed of E-glass/Epoxy and PVC foam were investigated by both experimental and analytic methods. The static load capabilities and failure modes predicted by the theory of beam on elastic foundation showed good agreement with the three-point bending test results. Using the experimental and analytic results, the static failure mode map was constructed. Also, the impact failure modes and the impact energy absorption characteristics of the sandwich beams were studied by the impact test and the finite element analysis. From the test result, it was found that the face failure mode was favorable for the high impact energy absorption. Using the experimental and finite element analysis results, the impact failure mode map was constructed.