STATIC ANALYSIS OF VARIABLE STIFFNESS LAMINATES BASED ON MIXED FINITE ELEMENT

For variable stiffness laminated structures, the theory of plates and shells or the conventional displacement finite element method are mostly used to analyze the mechanical behavior. Unlike the displacement element, the noncompatible generalized partial mixed element introduces displacement and stress boundary conditions at the same time, which improves the accuracy of stress results, and the boundary stress is more in line with the real situation. A modified noncompatible generalized partial mixed element model suitable for variable stiffness laminated structures is proposed by extending the theory of noncompatible generalized partial mixed element of pure elastomer. The comparison with the results from ABAQUS shows that the method in this paper has good applicability, and the numerical results are more accurate with sparser mesh. The influence of fiber laying angle on the in-plane displacement field of variable stiffness laminated plates is analyzed through numerical examples, which may be helpful for the design of variable stiffness structures.