Drop-Weight Impact Studies of GLARE 5 Fiber-Metal Laminates

Impact responses and damage induced by a drop-weight instrument on GLARE 5 fiber-metal laminates with different layup configurations and geometries were studied. The damage characteristics were evaluated using both the nondestructive ultrasonic and mechanical sectioning techniques. Only the contour of entire damage area could be obtained using ultrasonic C-scan whereas more details of damage were provided through the mechanical cross-sectioning technique. It was found that failure mode changed with varying stacking sequence. GLARE 5 made of unidirectional fibers had the worst impact resistance; followed by cross-ply and angle-ply configurations, while the quasi-isotropic lay-up showed the best resistance to impact. Finally, influence of different geometries was considered. The results show that by introducing circular geometry, damage patterns and impact behaviors were changed. This was especially apparent for panels with the quasi-isotropic layup configuration.