Bending-twisting coupled structures based on composite laminates with extension-shear coupling effect

To improve the mechanical properties of bending-twisting coupled structures, the necessary and sufficient conditions for composite laminates with extension-shear coupling effect which contribute to the bending-twisting coupled structures are deduced. Then the analytical expressions for torsional distortion of bending-twisting coupled structures are deduced. The Differential Evolution algorithm is used to optimize the bending-twisting coupled structures for the purpose of maximizing torsional distortion, the stacking sequences of two extension-shear coupled laminates are obtained through calculation. Lastly, the applicability of simplified model is verified. The hygro-thermal stability, bending-twisting coupling effect and buckling load of bending-twisting coupled structures are verified via simulation. The yield strength is analyzed based on Tsai-Wu criterion.