A constitutive model of dual-component shape memory hybrids considering isothermal crystallization and debonding damage

Abstract

The concept of shape memory hybrids (SMHs) has been proposed in recent years as a new kind of shape memory materials. By carefully selecting the actual composition of SMHs, some special features could be realized to meet the requirements of particular engineering applications. However, in terms of simulation, conventional constitutive models for shape memory polymers (SMPs) struggle to precisely characterize certain unique properties of these SMHs. In this study, a constitutive model integrating both rheology and phase transition conceptions is proposed to simulate the mechanical behaviors including shape memory effect of dual-component SMHs. The specific yielding phenomenon at room temperature of SMHs, induced by debonding between two components, is explained by incorporating particle-damage theory. Compared with the experimental and simulated results from a kind of SMH which can be programmed isothermally, it is indicated that the proposed constitutive model effectively captures the mechanical characteristics as well as the shape memory behaviors and the phenomenon of particle debonding damage of these SMHs. Furthermore, the influences of different parameters, such as component proportion, temperature, and isothermal shape fixing time, on these SMHs are discussed as well. This versatile model offers valuable insights for the development of constitutive models in this field as it is not limited to this case only, but could also be promoted to various different kinds of dual-component SMH systems.