Simulation-aided development and qualification of a novel Thermoclinch joining technology for multi-material design with textile-reinforced thermoplastic composites

该项目的目的是模拟辅助开发一种新的基于成形的连接技术，用于热塑性复合材料的金属-塑料混合结构。在所设计的热铆接连接方法中，局部加热和塑化的复合材料通过金属部件中的开口模制，并扩散到具有限定纤维结构的底切。为了提高加工能力和缩短周期，通过将切割和加热的预处理步骤集成到实际的连接过程中，进一步发展了热铆接技术。因此，为先进的热机械加工开发了合适的连接设备，成型工具和工艺参数，其特征是纺织增强热塑性塑料的大塑性变形。基本理论，以玻璃纤维增强聚丙烯（GF/PP）和钢板为例进行了工艺和实验研究。在此基础上，替代材料组合脆性碳纤维增强材料和低粘性基体系统，如聚酰胺进行评估的在线热铆接process.The现实的预测的变形和破坏行为的热铆接接头是基于一个耦合的过程和结构模型的数值多尺度过程模拟策略。该仿真工具被扩展到集成默认的层合结构和材料组合，用于接头的结构分析和接头性能的数值预测。对于热铆接接头的详细分析，将制造选定的接头配置，并通过表征接头形状在宏观水平上进行评估，通过评估变形引起的局部纤维排列在微观水平上进行评估。对于接头的广泛结构确定，计算机断层扫描被应用，并另外用于验证过程模拟，特别是相对于所得到的接头特性。此外，原位计算机断层扫描还用于深入了解拉伸剪切和剥离载荷下的连续损伤行为。使用单搭接接头（拉伸剪切和剥离载荷）的标准化测试方法，对工艺特定影响和接头性能之间预期的复杂相互作用进行数值和实验评估。在此基础上，质量保证方法的生产混合接头可再现的关节性能。基于对这种新型连接方法的综合评价，推导出了结构节点荷载适应性设计的具体材料设计规则。此外，制定了在线热固定装置的结构设计准则。

Aim of the proposed project is the simulation-aided development of a novel forming-based joining technology for metal-plastic hybrid structures with thermoplastic composites. Within the devised joining method thermoclinching, the locally heated and plasticised composite is moulded through an opening in the metallic part and spread to an undercut with defined fibre architecture. With the aim of raising process capabilities and reducing cycle times, the thermoclinching technology is further developed by integrating the pre-processed steps of cutting and heating into the actual joining process.Therefore, adapted joining devices, forming tools and process parameters are developed for the advanced thermo-mechanical process, which is characterised by large plastic deformations of the textile reinforced thermoplastic.The fundamental theoretical, technological and experimental investigations are performed on the example of the material configuration glass-fibre reinforcedpolypropylene (GF/PP) and steel sheet metal. Based on this, alternative material combinations with brittle carbon fibre reinforcement and low-viscous matrix systems like polyamide are evaluated for the inline-thermoclinching process.The realistic prediction of the deformation and failure behavior in thermoclinching joints is based on a numerical multiscale process simulation strategy with coupled process and structural models. The simulation tool is extended to integrate default laminate structures and material combinations for the structural analysis of the joints and the numerical prediction of joint properties.For the detailed analysis of the thermoclinching joints, selected joint configurations will be manufactured and evaluated on the macroscopic level by characterising the joint shape and on the microscopic level by evaluating the deformation-induced local fibre alignments. For the extensive structure determination of the joints, the computed tomography is applied and additionally used to validate process simulations, especially with respect to the resulting joint characteristic. Furthermore, in-situ-computed tomography is used for an in-depth understanding of the successively damage behavior under tension-shear and peel loading.The numerical and experimental evaluations of the anticipated complex interaction between process-specific influences and joint properties are performed using standardized test methods for single-lap joints (tension-shear and peel load). On that basis, quality assurance methods are derived for producing hybrid joints with reproducible joint properties. Based on a comprehensive assessment of the novel connection method, material specific design rules for a load adapted design of structural joints are deduced. In addition, constructive design guidelines for inline-thermoclinch-installations are worked out.