Simulation-assisted development of material-, load- and process-specific inserts for thermoplastic composites

连接区域的设计和尺寸通常是成功开发汽车工业、机器和工厂制造的混合轻质部件的关键因素。金属载荷引入元件作为连续纤维增强塑料的可靠和有效的连接技术的应用在大多数轻量化设计领域被广泛接受。迄今为止，这种插入件要么必须在部件制造期间以高努力嵌入，要么需要额外的工艺步骤进行集成。通过一种新的自动化工艺，现在可以在利用温成形技术的部件制造过程中集成插入件。在整个过程中，增强纤维通过锥形销重新定向，从而产生具有局部变化的纤维取向和纤维体积分数的复杂材料结构。在这种接头的设计过程中，必须考虑荷载引入区的材料结构，以可靠地描述承载性能。然而，连续的多尺度加工和结构模拟方法还没有，严格的实验表征将需要一个不适当的testingefforts.因此，在这个项目中，一个实验辅助的温成形连接区的数值表征方法应开发，使一个有效的系统设计的负载应用区与嵌入式插件。因此，对于每个插入件设计，仅制造一个代表性的接合区，然后通过计算机断层扫描进行分析，以确定微观尺度上的局部纤维取向和纤维含量。基于这些数据，确定局部材料特性并将其实施到有限元模型中。使用该模型，现在可以对所有设计相关的载荷情况下连接区域的变形和损坏行为进行数值分析。然后，应使用这些结果为荷载施加元件、材料结构和工艺特定方面提出系统设计流程。

The design and dimensioning of joining zones often represents a key factor for the successful development of hybrid lightweight components for automotive industry, machine and plant manufacture. The application of metallic load introduction elements as a reliable and efficient joining technique for continuous fibre reinforced plastics is widely accepted in most areas of lightweight design. To date, such inserts either have to be embedded with high effort during component manufacturing or need an additional process step for integration. By means of a novel automated process inserts now can be integrated during component manufacturing utilising warm forming technology. Throughout this process, the reinforcing fibres are reoriented by a tapered pin, resulting in a complex material structure with locally varying fibre orientations and fibre volume fractions. In the design process of such joints, the material structure in the load introduction zone has to be considered to enable a reliable description of the load-bearing behaviour. However, continuous multi-scale processing and structural simulation methods are not available yet, and a strictly experimental characterisation would require an inappropriate testing effort.Hence, within this project an experimentally-assisted numerical characterisation method for warm formed joining zones shall be developed, enabling an efficient systematic design of load application zones with embedded inserts. Thereby, for each insert design only one representative joining zone is manufactured and then analysed by computed tomography to determine local fibre orientations and fibre contents on microscale. Based on this data the local material properties are determined and implemented into an FE model. With this model, the deformation and damage behaviour of the joining zone can now be numerically analysed for all design-relevant loading scenarios. These results shall then be used to propose a systematic design process for load application elements, accounting material structure and process specific aspects.