Numerical and experimental investigations of thermal riveting of polymeric materials

聚合物材料热铆接的数值和实验研究

• 批准号: 413515815
• 负责人: Professorin Dr.-Ing. Birgit Awiszus
• 金额: --
• 依托单位: Professur Kunststoffe
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/413515815?language=en
• 关键词: Numerical; experimental; investigations; thermal; riveting

Due to the comparison between experiment and simulation, the geometrical-constructive, material and process-technical factors influencing thermal plastic riveting can be realistically recorded and modeled. The usage of numerical models should increase the process transparency and should lead to manageable design criteria for plastic riveted joints. The classification of thermal riveting methods are based on the type of energy input like the hot air riveting (convection) and the hot forming (heat conduction). Based on the experimentally determined material behavior, numerical models have to be developed which simulate the thermal riveting processes close to reality. The aim is to characterize the process-specific interactions between the heating and forming behavior and to link them with the resulting material structure. Furthermore, the mechanical joining properties have to be correlated with the non-measurable or difficult-to-measure physical parameters (e.g. stress, strain) using the FEM. These physical parameters are depending on the used riveting pin geometry, the stamp design and the process parameters. In addition, the quasi-static strength characteristics determined in the simulation and in laboratory tests are to be transferred to the operating behavior under dynamic load. It should be scientifically explained, under which restrictions the short-term properties, determined by simulation and experiment, can be used to evaluate the long-term properties. For this purpose, vibration tests (shakers), dynamic head tensile tests and long-term investigations under the influence of media and temperature are carried out. Fracture-mechanical, light microscopic and thermal analyzes are done to characterize the failure modes, the failure process and the material condition.

由于实验与模拟之间的比较，影响热塑铆接的几何结构、材料和工艺技术因素可以被真实地记录和建模。数值模型的使用应提高过程透明度，并应为塑料铆接接头提供易于管理的设计标准。热铆接方法的分类是基于能量输入的类型，例如热空气铆接（对流）和热成型（热传导）。基于实验确定的材料行为，必须开发模拟接近现实的热铆接过程的数值模型。目的是表征加热和成型行为之间特定于过程的相互作用，并将它们与最终的材料结构联系起来。此外，机械连接性能必须与使用有限元法无法测量或难以测量的物理参数（例如应力、应变）相关联。这些物理参数取决于所使用的铆钉几何形状、冲压设计和工艺参数。此外，在模拟和实验室测试中确定的准静态强度特性将被转移到动态负载下的操作行为。应该进行科学的解释，在这种限制下，通过模拟和实验确定的短期特性可以用来评估长期特性。为此，进行了振动试验（振动台）、动态头部拉伸试验以及介质和温度影响下的长期研究。通过断裂力学、光学显微镜和热分析来表征失效模式、失效过程和材料状况。