The term forming is defined by DIN 8580 as manufacturing by a three dimensional or plastic modification of a shape with a controlled geometry while retaining its mass and material cohesion. Within in the project the manufacturing of flanged holes will be investigated. Flanged holes can be produced in any shape desired as bearing, fixturing or spacing elements and can be found on almost each sheet metal component. Flanged holes are produced by flange forming. According to DIN 8584-5 is flange forming defined as forming under combined tensile and compressive conditions using a punch and a drawing die to create an unbroken raised flange on pierced holes. In the scope of the project, the pilot hole is produced by shear cutting.
In production technology research and numerous industrial applications, the process chain shear cutting and flange forming has been continuously optimized over the past decades. In the meantime, a great deal of empirical knowledge is available, which contributes to quality assurance and helps to avoid the production of scrap. In particular, the increasing use of numerical methods for process design made a significant contribution here. Nevertheless, stochastically occurring edge cracks are an unsolved problem. These are vertical cracks at the edge of the collar. Such cracks are caused by stochastic process fluctuations such as tool wear, material batch variations or sheet thickness fluctuations. With the currently available methods, a reliable prediction of this kind of edge cracks is not possible.
The new project is now pursuing an innovative approach to optimize the linking of shear cutting and flange forming processes in such a way that edge cracks are avoided. In the interdisciplinary interaction of forming technology and data science at Bayreuth and Chemnitz, the formation of edge cracks and their causes are to be precisely analyzed. On this basis, it will be possible to optimize the tools involved in the manufacturing processes in such a way that edge cracks will no longer or only rarely occur in the future. The basis for this research and development work will be an exact digital mapping of the process chain consisting of shear cutting and flange forming. All the relevant information for this, for example relating to materials, tools and manufacturing technologies, is to be integrated into the digital mapping using suitable data models.
"An important aspect of our planned research is the quality of the data on which we base the digital modeling. In data science, we now have technologically sophisticated techniques, such as process analytics and deep learning, that can be used to ensure and increase data quality. So far, these technologies have hardly been used for the further development and optimization of industrial forming processes. However, they offer the opportunity to make these processes significantly more effective and robust, to reduce manufacturing costs and – as a result of significantly lower production of scrap – to save material. We want to realize this opportunity in our project using the example process chain consisting of shear cutting and flange forming. The Priority Programme 2422 of the German Research Foundation, which is funding our research work in Bayreuth and Chemnitz with a total of about 788.000 euros, offers optimal framework conditions for this," says Prof. Dr. Agnes Koschmider, who holds the Chair of Business Informatics and Process Analytics at the University of Bayreuth.
COMPAMED-tradefair.com; Source: University of Bayreuth
