BUCKLING ANALYSIS OF LAMINATED COMPOSITE AND SANDWICH BEAMS

Based on the zig-zag theory, a two-node beam element is constructed. Moreover, this element is used to analyze the buckling problems of soft-core sandwich beams. The zig-zag theory used herein can become a priori condition for satisfying interlaminar continuity of transverse shear stresses, and the total number of unknowns is independent of the layer number of laminated beams. At the same time, Reddy’s theory as well as first-order theory is chosen for comparison. Numerical results show that beam element based on zig-zag theory is able to accurately predict critical loads of soft-core sandwich beams. However, Reddy’s theory and first-order theory obviously overestimate the buckling response of the special structures.