Abstract: The transverse initial cracking of the cross-ply laminates in90°ply by the action of the tensile loads in0° ply direction was studied by establishing a layering shear -lag model conjunct with the linear elastic fracture mechanics．The initial failure strains resulting from the thermally residual effect were then obtained．The calculated results are in a good agreement with those of the existing experiments and those obtained by finite element me-thod．The proposed model and methods supply a new way to carry out the failure analysis of fiber -reinforced composite laminate‚and the obtained results provide a theoretical basis for the further analysis of the multiple failure and ultimate fracture of lami -nates．

Key words: cross-ply laminate, transverse cracking, shear -lag analysis, energy method, failure strain