RESEARCH INITIATION: Modeling the Deformation Processing ofSolid Thermoplastics

为了充分利用固体热塑性塑料在成形过程中固有的速率依赖行为，将基于粘塑性有限元公式开发热塑性塑料在固相中的大变形加工模型。隐式时间积分方案将用于考虑成形过程中的弹性效应。将特别注意材料描述的形式和来源。考虑微观结构的模型将得到优先考虑，并期望在该领域作出一些发展努力。成形模型的应用将被用于热塑性成形过程，其实验数据可在文献中获得。将考虑到瞬态问题，如板材成型，以及可能被建模为稳态的过程，如挤压和冷拔。研究的最终结果应该是一个预测模型，并应用于热塑性塑料制造工艺的设计和开发。

A model for the large deformation processing of thermoplastics in the solid phase will be developed based on a viscoplastic finite element formulation in order to take advantage of the inherent rate- dependent behavior of solid thermoplastics during forming. An implicit time integration scheme will be used to account for elastic effects during forming. Special attention will be paid to the form and origin of the material descriptions. Models motivated by microstructural considerations will be given preference with some developmental effort expected in that area. Application of the forming model will be made to thermoplastic forming processes for which experimental data is available in the literature. Consideration will be given to transient problems, such as sheet forming, and to processes which may be modeled as steady-state, such as extrusion and cold-drawing. The ultimate product of the research should be a predictive model with application to the design and development of processes for the manufacturing of thermoplastics.