Tutorial: Thermomechanical constitutive modeling of shape memory polymers

Abstract

Shape memory polymers (SMPs) are one of the intriguing functional materials and have been widely and intensively studied. In order to apply these new polymers to load bearing engineering structures and devices, developing physics-based thermomechanical constitutive models is mandatory. The aim of this Tutorial is to demonstrate how to establish a thermomechanical constitutive model for SMPs. It begins with classifications of SMPs, followed by a discussion on the underlying physics for different SMPs. After that, three classical SMP thermomechanical modeling frameworks are introduced, which include the visco-elasto-plastic based rheological framework, the storage strain-based phase transition framework, and the representative unit cell based multi-branch framework. Next, three commonly adopted new model establishment methods are presented within these frameworks with detailed examples. Finally, future perspectives on this research direction are discussed. We hope that this Tutorial will help readers understand the roadmap from physics to mathematical modeling of SMPs.

Insight in thermomechanical constitutive modeling of shape memory polymers

“…However, these works mainly focus on amorphous one-way shape memory polymers (1W-SMPs), and only a few theoretical studies were conducted on semi-crystalline 2W-SMPs (Westbrook et al, 2010;Dolynchuk et al, 2014;Scalet et al, 2018;Yan et al, 2020b;Zeng et al, 2021). Basically, the detailed model frameworks accord with the modeling approach proposed by Yan and Li (2022). To be specific, these models were constructed by depending on Newton's law of motion and three basic physical laws Frontiers in Mechanical Engineering frontiersin.org Frontiers in Mechanical Engineering frontiersin.org (i.e., thermodynamics laws, conservation of mass, and conservation of momentum) and some auxiliary equations (see Figure 10).…”

“…A recent comprehensive review article was published by Yarali et al (2020). Most recently, Yan and Li published a tutorial paper on modeling SMPs (Yan and Li, 2022).…”

A 3D Anisotropic Thermomechanical Model for Thermally Induced Woven-Fabric-Reinforced Shape Memory Polymer Composites

“…The modeling approaches of SMPs can be divided into two main types: the phase-transition-modeling approach and the viscoelastic modeling approach. The phase-transition-modeling approach assumes that SMPs are composed of a rubbery phase and a glass phase and that shape memory behavior can be realized by provoking the temperature induced transition between the glassy phase and the rubbery phase [ 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. The viscoelastic modeling approach is based on the essential thermodynamic properties of SMPs and can be used to describe the entropy elasticity of SMPs above the glass transition temperature and the viscoelastic behavior below the glass transition temperature [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ].…”