A micromechanically motivated diffusion-based transient network model and its incorporation into finite rubber viscoelasticity
详细信息 查看全文
- 作者：Christian ; Linder ; ; ; linder@mechbau.uni-stuttgart.de ; Mykola ; Tkachuk ; Christian ; Miehe
- 关键词：Rubber viscoelasticity ; Transient network theories ; Micromechanics ; Brownian motion ; Non-equilibrium thermodynamics
- 刊名：Journal of the Mechanics and Physics of Solids
- 出版年：2011
- 出版时间：October 2011
- 年：2011
- 卷：59
- 期：10
- 页码：2134-2156
- 全文大小：1599 K
文摘
This paper presents the development of a physical-based constitutive model for the representation of viscous effects in rubber-like materials. The proposed model originates from micromechanically motivated diffusion processes of the highly mobile polymer chains described within the formalism of Brownian motion. Following the basic assumption of accounting for the elastic and the viscous effects in rubber viscoelasticity by their representation through a separate elastic ground network and several viscous subnetworks, respectively, the kinetic theory of rubber elasticity is followed and extended to represent also the viscous contribution in this work. It is assumed that the stretch probability of certain chain segments within an individual viscous subnetwork evolves based on the movement of the chain endpoints described by the Smoluchowski equation extended in this work from non-interacting point particles in a viscous surrounding to flexible polymer chains. An equivalent tensorial representation for this evolution is chosen which allows for the closed form solution of the macroscopic free energy and the macroscopic viscous overstress based on a homogenization over the probability space of the introduced micro-objects. The resulting model of the viscous subnetwork is subsequently combined with the non-affine micro-sphere model and applied in homogeneous and non-homogeneous tests. Finally, the model capacity is outlined based on a comparison with in the literature available experimental data sets.