Flat-clinch connection - a new connection with plane surface of die side

Coldforming, mechanical joining technologies, classified into joining by forming technologies, distinguish themselves by high economic viability and simple operation monitoring. Particularly, clinch technology needs no additional ancillary parts and one toolset is suitable for different kinds of materials and thicknesses. For this reason joining by clinching is used in many different areas of sheet metal processing industries. But at least one disadvantage of conventional clinch connections is the protrusion of the die-sided sheet metal, which is basically process-induced. Therefore, this kind of connection is not usable for exposed surfaces and functional areas, e. g. for piling up or sealing parts. Based upon scientific investigations about the process of clinching, a one-sided flat connection - joined by a single action forming process - could be developed. The main aim of this research is to join parts as simple as it could be done by clinching in order to keep a high economic viability of the whole process. Previous investigations have been exclusively carried out with experimental and practical tests. Because of many influencing variables to the process not all parameters and their interaction could be analysed in detail. For that reason finite element simulation of material flow and stress distribution should be used to improve this development. The paper deals with the development of this new joining technique using numerical simulation, the characteristic of the formed connections as well as the mechanical and technological properties of these joints. With this new kind of connection it is possible to expand the application area of joining by forming processes, especially for lightweight construction materials. The current level of development permits a direct industrial use