DAMPING PROPERTIES OF OPEN PORE ALUMINUM FOAMS PRODUCED BY VACUUM CASTING AND NaCI DISSOLUTION PROCESS

摘要

In this study,damping ratios of 3 samples made of aluminum foam material, which have different-density pores, were calculated, the effects pore density on damping were examined. Experimental modal analysis method was used for examining of the effects of the pore density on damping. In experimental modal analysis method, frequency charts were obtained by driving to the sample with a hammer. Through these frequency charts, damping ratios of each 3 samples were calculated with ME'scope VES program. It was observed in calculated damping ratios that pore density has influences on damping; thus, damping accordingly increases as the number of pores increases. It is seen that critical damping constant decreases as the material structure changes in terms of volume and density.