Abstract:Zig-zag theory is widely studied and used as continuity conditions of transverse shear stresses are a priori satisfied. However, some problems will be involved in the zig-zag theory. The C1 shape functions have to be required during its finite element implementation, so that it is difficult to construct higher-order element based on the zig-zag theory. Moreover, previous zig-zag theories are less accurate in comparison with three-dimensional elasticity solutions. If these problems are neglected, some improper conclusions might be drawn as these zig-zag theories are used to analyze the mechanical problems of laminated composites. By proposing an accurate C0-type zig-zag theory considering transverse normal strain, difficulties encountered by previous zig-zag theories will be overcome in this paper. Based on the proposed zig-zag theory, a three-node beam element is constructed to verify the performance of the proposed model.