Effect of Internally and Externally Ply Drop on Energy Absorption of Glass Fiber Reinforced Epoxy Composite Analyzed Using Numerical Methods

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Addis Ababa University


In a Ply dropped composite structures, Plies must be terminated or dropped off at discrete location over the part that improve the deformation and energy absorption capacity. In tapered structural parts thickness tapering cannot be achieved during a continuous way. Because of this tapered structures use either internally or externally ply drop types to create a required structural shape. Ply dropped composite used as impact absorption material for different application such as bumpers, armors, crush box, helmets, and disposable barrier shells and structures protection. However, the improvements of the capacity of impact energy absorption need a research to study the effect of different parameters and mechanisms on impact absorption capacity of composite materials. The main objective of this investigation is to study the effect of internally and externally ply dropped on the impact energy absorption of unidirectional glass fiber reinforced epoxy composite materials. Impact energy, load caring capacity and deformation of the flat, internally and externally dropped ply was analyzed. Based on the numerical approach using ABAQUS CAE software based on ASTM standards, at three different Impactor velocities of 2.51 m/s, 5 m/s and 10 m/s. From the analysis the specific energy stored on flat, internally ply drop, and externally ply drop was 13.23 KJ/Kg, 1.56 KJ/Kg and 25.74 KJ/Kg at 10 m/s respectively. The amount of peak load also recorded 54601.8 N, 10255.7 N and 50871.6 N and deformation of 0.0163 m, 0.012 m, and 0.022 m was recorded on flat, internally and externally dropped ply respectively. As compared the result of all ply arrangements by considered mass of the specimens’ external ply drop specimen had a better specific energy absorbed capacity of 25.74 KJ/Kg and load carried capacity of 50871.6 N at 10 m/s velocity impactor and deformation of 0.022 m. From this the analyses recommended that externally ply drop specimen has a better specific energy absorbed capacity.



Flat Specimen, Internally-ply drop, externally ply drop, Energy absorption capacity, Deformation, Reaction Force, Numerical approach