- 著者
-
藤川 正毅
山辺 純一郎
小石 正隆
- 出版者
- 一般社団法人 日本機械学会
- 雑誌
- 計算力学講演会講演論文集
- 巻号頁・発行日
- vol.2017, 2017
Industrial rubber, commonly used in the fabrication of tires and engine mounts, exhibits nonlinear viscoelastic behavior. In the design of these rubber products, it is important to capture the stress–strain responses under arbitrary loading conditions. However, the stress–strain responses exhibit complicated behavior, which depends on strain rate, strain history, strain amplitude, etc. The main purpose of this study is to develop a new constitutive model that captures the nonlinear viscoelastic stress–strain response of carbon-black-filled styrene-butadiene rubber vulcanizates (SBR-CB). In the assumed micro-mechanical network structure, we decomposed the isochoric free energy into the elastic equilibrium and the viscoelastic overstress response. Based on the results of our performance evaluation of various hyperplastic material models, we used an eight-chain model for the equilibrium network. For the nonlinear viscoelastic network, we used the micro-sphere model. The micro-stress/strain equation was assumed to be in simple phenomenological form, as reported by Miehe. For the revolution equation of the micro-inelastic strain, the Rendek and Lion model was employed. In addition, to reproduce the stress-strain relationship under from infinitesimal to 50% strain amplitude, the relaxation time depending on the strain amplitude of the free dangling chains was proposed as a new metric. The proposed model was able to practically and precisely reproduce the dynamic responses of SBR-CB25 under a wide range of applied strains and strain rates, was thermodynamically consistent for arbitrary deformation, could be implemented in commercial FEM software (Abaqus), and reproduced the stress-strain relationship under various experimental loading conditions.