C01 – Mech­an­ic­al join­ing without aux­il­i­ary ele­ments

Behind the background of an increasing demand for a resource-efficient production, lightweight constructions are a recent trend. Here, it is aimed to utilize the best material at the right place. Semi-finished products from continuous fibre-reinforced thermoplastics (CFRTs) offer superb weight-related mechanical properties and are gaining in importance alongside metallic lightweight materials. However, these materials have limitations, especially under high temperatures or abrasive wear. For this reason, multi-material systems are increasingly used to combine the specific strengths of the respective materials. However, due to the different physical and chemical properties, the joining technology represents a central challenge, causing established joining techniques to often reach their limits and a need for new technologies to emerge. An efficient approach to this is the joining without auxiliary parts by means of metallic pins, which can be produced by forming.

A pin is defined as a protrusion on one joining partner that ca be inserted in the second joining partner. Thereby, both a direct pin pressing as well as a combination of hole forming and pin insertion with subsequent caulking step are possible. The aim of the subproject is the fundamental investigation of described approach. Therefore, in the first phase the fundamentals of the pin manufacturing and joining process need to be examined.

It is possible to react to changing requirements on the joint through variation of the pin structure at the pin manufacturing step and to consequently allow the application in versatile process chains. Besides the pin manufacturing, the research of suitable joining processes is main goal. Thereby, in CFRT/Metal joining, different process routes with different heating strategies are to be in investigated: Via variable process strategies it becomes possible to react to different conditions (e.g. composition of the CFRT component). The gained knowledge of the pin manufacturing as well as the joining process and associated simulations will be fed back into the development of optimized pin geometries.

The exchange with other subprojects is essential for the validation of their developed damage models and dimension strategies. The final assessment of the pin geometries will be conducted based on the investigations of the joint properties.