Coupled thermomechanical model for strain‐induced crystallization in polymers
Coupled thermomechanical model for strain‐induced crystallization in polymers
复制标题
聚合物应变诱导结晶的耦合热机械模型
DOI：
10.1002/pamm.201900342
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Klinge
中科院分区：
文献类型：
--
作者：
Aygün;Klinge
某些聚合物（如天然橡胶）的结晶特征在于高应变引起的大分子中原子的特定几何排列。从结晶核开始，聚合物链离开其天然的缠结结构，伸展，折叠和堆叠。最终，他们建立了具有规则结构的区域，也称为laminate。在规划制造工艺时必须考虑该工艺，因为它会显著影响最终产品的机械和热性能。目前的贡献处理与未填充的聚合物，其中包括位移和温度作为全球的自由度，和网络的规整度作为一个内部变量的结晶的热机械模型。该模型的力学部分使用具有两个特殊功能的耗散势：第一，开发了物理一致的框架来模拟卸载阶段网络规则性的降低。其次，可视化了循环拉伸载荷下的微观组织演变。该模型的热部分基于热方程的解。由此产生的，耦合的热机械问题是解决在一个整体的方式。最后，选定的数值例子进行了比较与实验数据的天然橡胶无填料。
Crystallization in certain polymers, like natural rubber, is characterized by the specific geometrical arrangement of atoms in macromolecules caused by high strains. Starting from crystallization nuclei, polymer chains leave their natural entangled structure, stretch out, fold back and stack. Eventually, they build regions with a regular structure, also called lamellae. The process must be taken into consideration when planning manufacturing processes since it significantly influences mechanical and thermal properties of the final product. The present contribution deals with the thermomechanical model for crystallization of unfilled polymers, which involves displacements and temperature as global degrees of freedom, and the degree of network regularity as an internal variable. The mechanical part of the model uses the dissipation potential with two special features: Firstly, the thermodynamically consistent framework is developed to simulate the reduction of the network regularity during the unloading phase. Secondly, the microstructure evolution under the cyclic tensile load is visualized. The thermal part of the model is based on the solution of the heat equation. The resulting, coupled thermomechanical problem is solved in a monolithic way. Finally, selected numerical examples are compared with experimental data of natural rubber without fillers.
聚合物应变诱导结晶引起的微观结构演化研究
DOI：
10.1002/pamm.201800224
发表时间：
2018
期刊：
PAMM
影响因子：
--
作者：
Aygün;Klinge
通讯作者：
Klinge