Finite strain 3D thermoviscoelastic constitutive model for shape memory polymers

Abstract

A 3D thermoviscoelastic model is proposed to represent the thermomechanical behavior of shape memory polymers. The model is based on a physical understanding of the material behavior and a mechanical interpretation of the stress-strain-temperature changes observed during thermomechanical loading. The model is thermodynamically motivated and is formulated in a finite strain framework in order to account for large strain deformations. Model predictions capture critical features of shape memory polymer deformation and, in some cases, provide very favorable comparisons with experimental results. POLYM. ENG. SCI., 46:486 -492, 2006.

Experimental characterization and thermoviscoelastic modeling of strain and stress recoveries of an amorphous polymer network

“…Despite that fact, the number of papers dedicated to modeling shape memory polymers remains limited. We may divide the existing models into two categories: the models based on a bi-phasic representation of the material grounded on the rubbery/glassy state transition, first proposed by Liu et al (2006) and adopted by Chen and Lagoudas (2008), Qi et al (2008), Volk et al (2010), Gilormini and Diani (2012), and the thermoviscoelastic approach early introduced by Tobushi et al (1997) and improved by Diani et al (2006), Nguyen et al (2008), Castro et al (2010), Srivastava et al (2010), Diani et al (2012) and Yu et al (2012).…”

On modeling shape memory polymers as thermoelastic two-phase composite materials

“…An encouraging agreement was found with experiments, which confirmed that a thermoelastic model is able to capture the basic stress and strain evolutions. Extensions of the model to finite strain were proposed by Diani et al [15] and by Chen and Lagoudas [16], who also provided a small-strain version (Chen and Lagoudas, [17]). The original small-strain model of Liu et al [14] has also been revisited by Wang et al [18], who proposed a first combination of the model with the theory of composite materials.…”

Three-dimensional constitutive model for shape memory polymers using multiplicative decomposition of the deformation gradient and shape memory strains

“…Those models utilize the concept of strain storage (or non-mechanical strain), which has been often introduced to account for the shape memory effect (Baghani et al, 2014a;Chen and Lagoudas, 2008a, b;Diani et al, 2006;Guo et al, 2014;Liu et al, 2006). Previously developed multi-phase phenomenological constitutive models can be implemented into finite element analysis (FEA) software.…”

“…Most previously developed multi-phase constitutive models are phenomenological models that capture the thermo-mechanical deformation behavior of SMPs using a continuum element (Chen and Lagoudas, 2008a, b;Diani et al, 2006;Guo et al, 2014;Heuchel et al, 2013;Liu et al, 2006;Qi et al, 2008;Wang et al, 2009). The common feature of these phenomenological multi-phase models is generalization of three-dimensional (3D) problems based on continuum mechanics.…”