Experimental investigation on cenosphere-aluminum syntactic foam-filled tubes under axial impact loading

A new syntactic foam material was prepared by screening three different average particle sizes of cenospheres (150, 200, and 300 µm) from industrial waste fly ash. Axial impact testing on syntactic foam filler and foam-filled tubes was conducted using a drop hammer test machine. The effects of parameters, such as the size of cenospheres and the impact velocity, on the mechanism of deformation, mechanical characteristics, and capacity for energy absorption of the specimen were investigated. On this basis, the differences in compressive properties exhibited by the syntactic foam-filled tubes under the two loading conditions were investigated. The results indicate that with the decrease in the average diameter of cenospheres, the initial peak crushing load and mean crushing load of foam-filled tubes increase, while the compression efficiency decreases. The specific energy absorption (SEA) of the syntactic foam-filled tube can reach 25 J/g. With the increase of impact velocity, the SEA of the specimen increases slightly. It was demonstrated that the syntactic foam-filled tube exhibits a higher effective energy absorption ratio under impact loading compared to quasi-static loading.