A thermoviscoelastic model for amorphous shape memory polymers: Incorporating structural and stress relaxation |
| |
Authors: | Thao. D. Nguyen H. Jerry Qi Francisco Castro Kevin N. Long |
| |
Affiliation: | aDepartment of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA;bDepartment of Mechanical Engineering, University of Colorado, UCB 427, Boulder, CO 80309, USA |
| |
Abstract: | A thermoviscoelastic constitutive model is developed for amorphous shape memory polymers (SMP) based on the hypothesis that structural and stress relaxation are the primary molecular mechanisms of the shape memory effect and its time-dependence. This work represents a new and fundamentally different approach to modeling amorphous SMPs. A principal feature of the constitutive model is the incorporation of the nonlinear Adam–Gibbs model of structural relaxation and a modified Eyring model of viscous flow into a continuum finite–deformation thermoviscoelastic framework. Comparisons with experiments show that the model can reproduce the strain–temperature response, the temperature and strain-rate dependent stress–strain response, and important features of the temperature dependence of the shape memory response. Because the model includes structural relaxation, the shape memory response also exhibits a dependence on the cooling and heating rates. |
| |
Keywords: | Shape memory polymers Structural relaxation Glass transition Thermoviscoelasticity Viscoelasticity |
本文献已被 ScienceDirect 等数据库收录! |
|