A shear-lag model for three-dimensional, unidirectional multilayered structures

A shear-lag model is derived for unidirectional multilayered structures whose constituents vary throughout the cross-section through the extension of an existing optimal shear-lag model suitable for two-dimensional planar structures. Solution algorithms for a variety of boundary conditions are discussed. Numerical predictions for a single-fiber composite and a unidirectional laminated composite are presented. Comparison of the predicted interfacial shear stresses and average normal stresses to finite element analysis demonstrates that this shear-lag model can be used to rapidly estimate the average normal stress distribution in the various constituents, although the interfacial shear stresses are less accurate. Possible applications and limitations of the new model are finally discussed.