Investigating Delamination Migration in Multidirectional Tape Laminates

Delamination migration was investigated at interfaces between plies with dissimilar fiber angle, θ, in composite tape laminates. The test method employed allowed to isolate and investigate a single delamination migration from a 0/θ interface into a stack of four plies oriented at θ. Tests showed that delamination propagation and migration varies across the specimen width. On one side, delamination appeared to grow at the initial interface, while on the opposite side, the damage progression was characterized by recurring kinking events initiating inside the specimen, before migration was completed. The occurrence and extent of kinking varies with the fiber angle. The experimental results showed that delamination migration is affected by the local stress state at the delamination front, which varies across the specimen width, depending upon the fiber angle.