Variable stiffness property study on shape memory polymer composite tube

As a typical smart material, shape memory polymers (SMPs) have the capability of variable stiffness in response to external stimuli, such as heat, electricity, magnetism and solvents. In this research, a shape memory polymer composite (SMPC) tube composed of multi-layered filament wound structures is investigated. The SMPC tube possesses considerable flexibility under high temperature and rigidity under low temperature. Significant changes in effective engineering modulus can be achieved through regulating the environment temperature. Based on the classical laminated-plate theory and Sun's thick laminate analysis, a 3D theory method is used to study the effective engineering modulus and modulus ratio of the SMPC tube. The tensile test is conducted on the SMPC tube to verify the accuracy of the theoretical method. In addition, the effective engineering modulus and modulus ratio are discussed under different fiber-winding angles and fiber volume fractions of the SMPC tube. The presented analysis provides meaningful guidance to assist the design and manufacture of SMPC tubes in morphing skin applications.