Failure of aluminium beams under low velocity impact

An experimental Study of impact of blunt nose projectile at velocity varying from 11 to 114 m/s oil clamped aluminium beams of different thickness (span-to-thickness ratio 25 to 200) has been carried out. Tile data include no-failure as well as failure of beams. Three different modes of failure occurring at increasing velocity of strike have been observed viz. Type I (fracture at the point of strike), Type II (fracture at one or both supports) and Type III (fracture at the point of strike with bulging and turn around supports after fracture). The third mode of failure is it peculiar deformation pattern that has so far not been reported in literature. The velocity thresholds have been introduced to identify the mode of failure of beams. The maximum deflection of unfractured and fractured beams has been measured and compared with analysis [J. Liti N. Jones. Experimental investigation of clamped beam struck transversely by a mass. Int J Impact Eng 1987;6(4):303-35]. (C) 2007 Elsevier Ltd. All rights reserved.