Bending performance analysis of variable stiffness composite laminates

Abstract For fiber‐reinforced polymer structures, the out‐of‐plane stiffness is much lower than the in‐plane stiffness and is extremely prone to damage and instability. The potential of variable stiffness (VS) laminates was explored to enhance the stiffness in the thickness direction. Based on the finite strip method (FSM), a semi‐analytical solution for bending problems of laminates was derived, which is called the variable‐stiffness discrete strip (VSDS) method. By comparing with traditional constant stiffness (CS) laminates, the influence of design parameters of VS laminates on the bending shape and stress distribution of laminates under two load cases were studied. Combining the results of FE models, the accuracy of VSDS has been verified, and the strategy of VS layout configuration design to improve the bending resistance was proved. Highlights Variable stiffness discrete strips (VSDS) method was presented based on FSM. Bending performances of VS laminates under two load conditions were studied. The method has the ability to reduce the computation cost of bending problems. The solutions of VSDS agree well with the results of FE models. The improvement mechanism of VS laminates on bending resistance was explored.