Decisive for the cause of failure in the mechanical joining process is in particular the prevailing stress situation, the complex material behavior taking into account friction, plasticity and damage mechanisms as well as frequently incorrectly joined or overstressed joints. With regard to service loading, corrosion phenomena and the development and propagation of fatigue cracks have to be considered as well in order to avoid damage to mechanically joined structures under service loading. To analyze the properties of a clinched joint, trial-and-error methods and experience-based approaches have often been used so far. However, these are in general only rigidly valid for individual material-geometry combinations, so that the design of the clinching process can currently only react to external process changes to a limited extent and have to be carried out individually for each material combination.

Therefore, a reliable prediction of joinability requires a comprehensive methodology that considers the entire product life cycle from the material to be joined, through the manufacturing process, to the operation of the joint. This holistic approach is essential for an exact process simulation as well as a reliable prediction of load-bearing capacity and service life and is consequently an essential subject of the interdisciplinary cooperation within the working group “Modeling”. The TRR subprojects represented in this working group are doing research regarding holistic modeling approaches and, thus, contribute to the penetration of the complex cause-effect relationships in the mechanical joining of different materials (e.g. aluminum, steel and fiber composites). In this context, the numerical modeling of the entire joining process chain using the LS-Dyna software is aimed at, taking into account the design phase of the product, the joining process with damage modeling as well as the properties of the joint resulting from the operational phase (including corrosion and fatigue crack growth). A consistent consideration of these phases is necessary to manufacture clinched products in a process-safe manner and to be able to fulfill their functions over the entire service life. A simulation chain that takes into account all phases of the product development process of a clinched structure contributes significantly to the understanding of the complex interactions in the mechanical joining of different materials and, thus, ensures the joinability in versatile process chains.

• A01 - Fügbarkeitsprognose
• A03 - Werkstoffphänomenologie
• A05 - Schädigungsmodellierung
• B01 - Methodenentwicklung
• B03 - Korrosionsmodellierung
• B04 - Risswachstum
• C03 - Adaptive Reibelemente
• C04 – In situ Analyse