Composite laminated plates are often subject to low velocity impact which is known to cause internal ply delamination when subjected to in-plane compressive loads.  This instability causes the delamination area to grow leading to an overall decrease in compressive strength of the laminated plate.  This paper discusses a fracture mechanics based energy release rate approach to analyze the delamination buckling problem.  Chai et. al [1] solve a simplified one-dimensional “thin film” problem where the delamination is located near the plate surface.  The result of the simplified model is compared with a more general delamination depth case, solved in a similar manner, to establish its range of validity.  Using a similar method and results from the one-dimensional analysis, Chai and Babcock [2] analyze compression in a laminated plate for a two-dimensional delamination.

Reference
1.  Chai, H., Babcock, C., Knauss, W., “One Dimensional Modelling of Failure in Laminated Plates by Delamination Buckling,” International Journal of Solids and Structures, Vol. 17, No. 11, pp. 1069-1083, 1981.
2.  Chai, H., Babcock, C., “Two-Dimensional Modelling of Compressive Failure in Delaminated Laminates,” Journal of Composite Materials, Vol. 19, No. 1, pp. 67-98, 1985.