Mechanical analysis of carbon nanotube / shape memory polymer composites

Shape memory polymers (SMPs) have some advantages such as large deformability, large recovery ratio, and lightweight compared to shape memory alloys. However, low stiffness and thermal conductivity are demerits. To overcome these limitations, carbon nanotube reinforced shape memory polymer composites (CNT-SMPCs) have been researched. In this study, experimental and numerical studies of CNT-SMPCs are carried out, aiming to provide a design method of the composites, in particular for aerospace applications. CNT-SMPCs are prepared using a SMP resin and multi-walled carbon nanotube(MWCNT). Tensile and stress relaxation tests are conducted using universal tensile machine with a heating chamber to characterize the mechanical properties of CNT-SMPCs. Using threedimensional constitutive model, which was developed using multiplicative decomposition of the deformation gradient and shape memory strains, was used to simulate the SMP matrix inside CNTSMPCs, while linear elastic model was used for CNTs. Using cohesive zone model, their interface was modelled. Finally, the effect of volume fraction and orientation of CNTs on the mechanical behaviour of CNT-SMPCs including shape memory properties is simulated.