A hygro-thermo-mechanical constitutive model for hygrothermally activated shape memory polymers under finite deformations

A hygro-thermo-mechanical constitutive model for shape memory polymers filled with nano-carbon powder

“…It has been demonstrated that the approach is effective. Similarly, the moisture diffusion theory is incorporated into the internal state variable modeling approach in our previous work to describe the SMEs that can be triggered both by temperature and moisture [30,31]. It was found that the model results fit well with the test data for both thermally activated and moisture activated SMEs.…”

“…Secondly, the basic thermodynamic potential depends on the temperature, the stress and, a set of internal variables [36]. In our previous work, it has been proved that the modeling approach based on thermodynamics with internal state variables can be effectively extended to describe the hygro-thermomechanical SMEs of the hygrothermally activated SMPs [30]. Therefore, a similar modeling approach is still used here to characterize the SMEs of the hygrothermally activated SMPs filled with nano-carbon powder as shown in Figure 1.…”

“…For simplicity, the modeling approach for structural relaxation will be briefly introduced here. The detailed deduction procedure can be found in Gu et al [30].…”

Electro-thermo-mechanical modeling of shape memory polymers filled with nano-carbon powder

“…It has been demonstrated that structural and stress relaxation characterize the procedure of molecular chains from the non-equilibrium configuration to an equilibrium state for the thermally induced SMPs (Lion et al, 2010(Lion et al, , 2011. Based on thermodynamics with internal state variables, our previous modeling work can successfully describe the hygro-thermomechanical properties of the hygrothermally induced SMPs (Gu et al, 2020). For amorphous polymers, the thermally induced, water-induced, and electrically induced SMEs share the same activation mechanism.…”

“…For the first time, the electro-thermo-mechanical properties of electrically induced SMPs filled with nano-carbon powder are systematically studied in this study. In our previous work, the hygro-thermo-mechanical properties of the hygrothermally induced SMPs were successfully described by the modeling approach based on thermodynamics with internal state variables (Gu et al, 2020). For the SMP with well-dispersed nano-carbon powder, it is reasonable to be considered as isotropy.…”