Composite Materials

· Crack propagation in a glass fiber-polyester resin composite is shown.
· The crack initiates in a high stress region of the matrix, which debonds from the fiber.
· Crack propagation passes through similar regions in the composite, the open crack having a stress concentration at its sharp termination.
· When the crack tip reaches a matrix zone relatively free of fibers, crack blunting and resin flow occurs.

From: Hull, "Introduction to Composite Materials," Cambridge (1992)