Response of metallic cylindrical sandwich shells subjected to projectile impact-Experimental investigations

The dynamic response of peripherally clamped cylindrical sandwich shells with two aluminum face-sheets and an aluminum foam core has been experimentally investigated using an improved loading technique. The resistance to impact loading is assessed by using the permanent transverse deflection at central point of back face-sheet of the sandwich shell. The comprehensive deformation and failure modes of specimens were classified and analyzed in term of face-sheets and core, and then the failure mode map of specimens was presented. Effects of impulse, face-sheet thickness, core thickness and relative density of core on the resistance to impact loading were discussed in detail. Deformation mechanism of sandwich shells subjected to projectile impact was explored based on the results of strain gauges adhered on the face-sheets. Results indicate that both the deformation/failure modes and back face-sheet deflection of sandwich shells are sensitive to impulse and their geometrical configurations, and the curved sandwich structures have an evident advantage on the resistance to deform, to the flatted sandwich panels. The experimental results have important reference value to the further study and engineering application of metallic sandwich structures.