DEVELOPMENT OF CLOSED CELL FOAMS TO ATTENUATE UNDERWATER SHOCK WAVES

LIGHTWEIGHT MATERIALS WHICH CAN PROTECT EQUIPMENT AND STRUCTURES FROM THE DAMAGING EFFECTS OF UNDERWATER EXPLOSIONS WOULD HAVE MANY APPLICATIONS ON SUBMARINES AND SURFACE SHIPS. CLOSED CELL RIGID EPOXY FOAM WITH APPROXIMATELY 55% AIR VOID CONTENT BY VOLUME HAS BEEN SHOWN TO ATTENUATE THE PEAK PRESSURE IN SHOCK WAVES DUE TO AN UNDERWATER EXPLOSION. THE OBJECTIVE OF THIS PHASE I FEASIBILITY STUDY IS TO DEVELOP MATERIALS AND MANUFACTURING PROCESSES TO INCREASE THE VOID CONTENT OF STRUCTURAL FOAMS UP TO 75% OR 85% AND INCREASE DAMPING BOTH OF WHICH ARE EXPECTED TO ENHANCE THEIR SHOCK ATTENUATION PROPERTIES. VARIOUS MANUFACTURING PROCESSES INCLUDING CENTRIFUGAL CASTING WILL BE ADAPTED TO PRODUCE STRUCTURAL FOAM SAMPLES WITH HIGH VOID CONTENT AND DAMPING. THE SHOCK ATTENUATION PROPERTIES WILL BE ESTIMATED USING COMPUTER MODELS AND MEASURED MATERIAL PROPERTIES OF THE FABRICATED SAMPLES.