Physically motivated FEM material law based on the material and processing induced morphology during injection molding by unreinforced as well as reinforced thermoplastic materials

基于物理驱动的 FEM 材料定律，基于非增强和增强热塑性材料注塑过程中的材料和加工诱导形态

• 批准号: 284349961
• 负责人: Professor Dr.-Ing. Michael Gehde (†)
• 金额: --
• 依托单位: Professur Festkörpermechanik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/284349961?language=en
• 关键词: Physically; motivated; FEM; material; law

There is a deficit in the repatriation of existing constitutive laws for semi-crystalline thermoplastics on basic physical coherences and processes, such as their crystallization. This impedes their applicability in FE-simulations. Furthermore, the basic mechanisms and determining factors for the crystallization and their effects on macroscopic material behavior are only partially understood. Accordingly, it is not possible to reliably control the crystallization process in relation to a predefined crystallinity degree. This opposes a reliable and precise simulation of semi-crystalline thermoplastics, which is the basis for computer-assisted development and optimization of hybrid plastic-metal-composites.The overall objective of the project is to understand the reasons and effects of the crystallization in hybrid-structures. These studies should be done on unreinforced and reinforced (second period of founding) thermoplastics. The results are required to control the crystallization during the manufacturing process and to create a physically based constitutive law.The aim of the proposed research project is the controlled crystallization of the unreinforced thermoplastics PA6 and PBT. One step to reach this aim is the experimental characterization of the crystallization peculiarity with different, precisely defined process parameters and material properties, like melt and mold temperature, tool topography and rheological properties, by using partially new inspection methods. Another aim is to create a computer simulation, based on a "multi-particle system" with self-organized structure formation to reproduce the solidification of semi-crystalline thermoplastics as well as to perform an array of systematical simulations. It should be possible to identify experimentally graspable characteristics and correlations. Therefore, the simulation allows to access experimentally inaccessible information about the crystallization process and enables its manipulation.Based on the state of the art, existing constitutive laws and models are transferred into the continuum mechanic representation together with experimental results of the macroscopic polymer characterization, the optical structure analyzes, the calorimetric crystallization analyzes and the simulation of crystallization by using the forecast model. The arising representation can be integrated into a new material model. To implement the experimental results into a FEM simulation for the development and optimization of the hybrid-thermoplastic-metall composites is the final objective.

对于基本物理相干和过程（例如结晶）的半晶热塑性塑料的现有本构定律的归还存在赤字。这阻碍了他们在Fe模拟中的适用性。此外，仅部分理解了结晶的基本机制和确定因素及其对宏观材料行为的影响。因此，与预定义的结晶度相关的结晶过程不可能可靠地控制。这反对半晶热塑性塑料的可靠，精确的模拟，这是计算机辅助开发和优化杂交塑料 - 金属材料的基础。该项目的总体目的是了解结晶在杂交结构中的原因和影响。这些研究应以未加固和加强（建立的第二阶段）热塑性进行。需要结果以控制制造过程中的结晶并创建基于物理的构成定律。拟议的研究项目的目的是未增强的热塑性PA6和PBT的控制结晶。达到这一目标的一步是使用部分新的检查方法，具有不同的，精确定义的过程参数和材料特性，例如熔体和模具温度，工具形态和流变特性的实验表征。另一个目的是基于具有自组织结构形成的“多粒子系统”来创建计算机仿真，以重现半晶热塑料的凝固以及执行一系列系统模拟。应该可以识别实验上可掌握的特征和相关性。因此，该模拟允许访问有关结晶过程的实验性无法访问的信息，并实现其操作。基于最新的状态，现有的本构法律和模型被转移到连续机械师的表现中，以及宏观聚合物的实验结果以及通过孔隙结构分析，通过热量的结晶分析和模拟晶体来进行晶体的晶体化，并将其用于晶体。出现的表示形式可以集成到新的材料模型中。最终目标是将实验结果实施到FEM模拟中，以开发和优化杂种 - 塑料 - 甲列组合材料。