Cantilever sandwich beams with pyramidal truss cores subjected to tip impact

Experiments were conducted to investigate the deformation of cantilever sandwich beams with pyramidal truss cores subjected to impact by a projectile at their tips. A new technique was employed to the fabrication of sandwich beams with pyramidal truss cores. For a better observation of large deformation of specimens during impact process, a high-speed digital video camera was successfully used to capture the instant shapes of the deformed beams. A projectile collection device was designed and installed to avoid the projectile flying away from the beam tips after impact and thus the kinetic energy imparted to the beams was measurable. The experiments show that the sandwich beams have a superior shock resistance compared to the monolithic beams of the same material and mass. Further, finite element simulations were performed to gain insight into the deformations and plastic energy absorptions in the sandwich beams.