Variable modulus materials based upon F2MC reinforced shape memory polymers

The performance of a new variable modulus composite material based upon shape memory polymer (SMP) reinforced with fluidic flexible matrix composite (F2MC) tubes is investigated in this research. The new composite material is a unique combination of shape memory polymers acting as the matrix material with reinforcing embedded F2MC tubes. The recently developed F2MC tubes are small diameter tubes capable of potentially achieving more than three orders of magnitude change in effective stiffness through utilization of anisotropic flexible matrix composite (FMC) tubes, a high bulk modulus internal working fluid, and simple valve control. Similarly shape memory polymers can achieve more than three orders of magnitude change in stiffness through temperature regulation. To investigate the SMP-F2MC variable modulus composite material, an analytical model of the SMP-F2MC variable stiffness composite material is developed and design studies are performed. The results demonstrate that the new material system can achieve a wider range and greater selection of modulus values than the SMP or F2MC systems alone. Experimental results show good agreement with analysis.