Hilfsfügeteilfreies Fügen

Funding period:

Start: 1. July 2019
Ende: 30. June 2027

Abstract

The aim of this project is to conduct fundamental scientific research into joining without auxiliary element using metallic pin structures produced by forming technology, which are pressed into the joining partner or caulked after insertion into a perforated joining partner, and the joint properties that can be achieved with this. This includes the development of a fundamental understanding of the acting mechanisms with a focus on feasibility in phase 1, the optimisation of the pin structure with regard to geometry and arrangement as well as the joining process for the targeted adjustment of joining properties in phase 2 and the transferability of the technology to an extended range of applications in phase 3. The aim in phase 1 is therefore to develop a fundamental understanding of the extrusion of defined metallic pin geometries from the sheet plane using local material accumulation in order to be able to determine local changes in the material properties, such as strength. Simultaneously, different process control strategies for joining metal and FRP as well as different metals will be fundamentally researched and process windows will be derived.In the case of FRP, various process routes will be investigated with a focus on fibre-friendly injection of the pin structures or hole forming for caulking of the pin structures without delamination of the FRP. Ultrasound, vibration, infrared radiation or combinations of these methods are used to melt the matrix with the goal of identifying suitable process routes and generating an understanding of the mechanisms at work.  Based on the findings of the pin manufacturing and the results regarding the joining processes, a fundamental understanding of the process will be developed, which will allow the further development of the pin geometry and the definition of suitable simple, regular pin arrangements and dimensions in the next step. In order to meet the different requirements of the pin manufacturing process and the joining method, the adaptability of the tool and joining technology is essential. Accordingly, the adaptation on the tool side and the specific process control during pin production will be investigated in order to demonstrate the possible variations. In addition, the adaptability of the joining operation will be achieved by adapting the process control, especially in the case of metal-FRP joints, in order to react to different conditions, such as the fibre layer and layer structure of the FRP. Finally, the direction-dependent joint properties and the application behaviour of the multi-material joints joined with the developed pin geometries will be characterised and evaluated depending on the pin dimensioning and arrangement in order to identify the decisive influencing factors on the joint properties.

Funding period:

Research groups

• Manufacturing Processes

Publications