Abstract: The FEM (finite element modal) of double delaminated composite plate is constructed using the technology of reference surface finite element. The effects of size and location of delamination on the buckling of the plate are studied under different boundary conditions. The numerical results show that the buckling loads of the double delaminated laminate depend on the weakest subdelamination thickness within the delaminated region and exhibit that an identity of the buckling loads exists between the double and single delaminated plates under the given region. The variable regularity of buckling loads of the double delaminated plate can be clearly explained from the isoline figure in this paper.

Key words: delaminated damage, buckling, finite element, double delamination, r eference sur face element