A thermodynamically-consistent 3D constitutive model for shape memory polymers
A thermodynamically-consistent 3D constitutive model for shape memory polymers
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DOI：
10.1016/j.ijplas.2012.01.007
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发表时间：
2012-08-01
影响因子：
9.8
通讯作者：
Sohrabpour, S.
中科院分区：
文献类型：
--
作者：
Baghani, M.;Naghdabadi, R.;Sohrabpour, S.
形状记忆聚合物的应用日益广泛，促使了这些材料的本构模型的发展。在这项工作中，我们提出了形状记忆聚合物在时间相关的多轴热机械载荷下的小应变下的三维本构模型。该推导是基于应变的加性分解，并以克劳修斯-杜昂不等式的形式满足热力学第二定律。在本构模型中，推导了冷却和加热热力加载过程中内部变量的演化规律。所提出的模型也充分考虑了粘性效应。进一步，我们以隐式形式给出了演化方程的时间离散形式。通过将预测结果与文献中不同的实验数据进行比较，验证了模型的有效性。最后，利用有限元方法求解了三维梁和形状记忆聚合物医用支架两个边值问题。(C) 2012 Elsevier Ltd.版权所有。
The ever increasing applications of shape memory polymers have motivated the development of appropriate constitutive models for these materials. In this work, we present a 3D constitutive model for shape memory polymers under time-dependent multiaxial thermomechanical loadings in the small strain regime. The derivation is based on an additive decomposition of the strain into six parts and satisfying the second law of thermodynamics in Clausius-Duhem inequality form. In the constitutive model, the evolution laws for internal variables are derived during both cooling and heating thermomechanical loadings. The viscous effects are also fully accounted for in the proposed model. Further, we present the time-discrete form of the evolution equations in the implicit form. The model is validated by comparing the predicted results with different experimental data reported in the literature. Finally, using the finite element method, we solve two boundary value problems e.g., a 3D beam and a medical stent made of shape memory polymers. (C) 2012 Elsevier Ltd. All rights reserved.