Experimental studies on thin sandwich panels under impact and static loading

Abstract

Several thin sandwich panels (thickness close to 3 mm) of different configurations were studied to explore an alternative material for the outer body of various machines and appliances such as automobile, refrigerator, washing machine, lathe machine, drill press, cupboards, light furniture, etc. Three types of sandwich panels with the outer face sheets made of glass fabric/epoxy were fabricated for the present study: (1) XM-Core panel was made of polyester foam Coremat XM/epoxy as core material, (2) Xi-Core panel was made of polyester foam Coremat Xi/epoxy as core material, and (3) J-Core Panel was made of layers of Jute fabric/epoxy as core material. A very thin transition layer of glass chopped strand mat/epoxy was provided between the face sheets and the core to improve their bonding strength. The sandwich panels were analyzed for low velocity normal impact loading under a drop weight impact test set up and transverse static loading under universal testing machine. Damage area, indentation depth and permanent depression over damage area, and failure modes were observed under incident impact loading. The transverse static test was performed to observe load versus deflection relation and to characterize the flexural strength and stiffness.