The application of mechanical joining technology offers the possibility to join mixedmaterial structures with a wide range of requirement profiles and material-geometry combinations with varying geometric and material-specific parameters. A complete validation of the joinability in versatile process chains along the manufacturing process of joining parts, joining process and service life is currently not possible due to the limited visibility of the processes from outside, the high number of combinable tool variants as well as variable force and path based process parameters. A versatile process chain, i.e. a sequence of all the necessary processes and process steps for production, enables targeted changes to be made to the semi-finished product, the joining zone, the component or the joining process that exceed the originally planned extent while still guaranteeing the joinability. In detail, it leads to a unique joint with its own mechanical property profile with regard to different types of loading, which, against the background of the resulting very high number of material-geometry combinations, makes it impossible to ensure the joinability using the conventional experimental approach.The vision of the subproject is the development of methods for a complete prognosis of the joining process along the process chain Mechanical joining in versatile process chains. Concretely, that means that the entire mechanical property profile (joining safety) is to be predicted from different load directions, such as shear and tension and load-time functions quasi-static, impact or cyclic, under consideration of the joining part materials changing in type and condition (joining suitability) and joining processes adapted to them (joining possibility). On the one hand, methods are developed in SP A01 and on the other hand, it integrates the methods developed in the TRR as well as those developed by other SPs in order to achieve the necessary wholeness with regard to the joining part materials, joining methods and service conditions. For this purpose, combined methods from experimental verification methods and simulation models, which describe the joint behaviour on the basis of the material characteristics, have to be developed in order to open up the fundamental principles of working and to comprehensively enable the prognosis on the basis of the simulation. The methods are finally used for the development of flexibility and robustness improvement methods for versatile process chains with varying input variables such as material, geometry and process. In the first phase, a simulation strategy will be developed which virtually models all three process steps and allows the transfer of the relevant status variables, such as geometry, material hardening and damage, for a continuous simulation of mechanical joining. This requires the definition of the interfaces between the subprocesses, which are still incompatible to a large extent today, and the closing of additional gaps for the realistic modelling of the joining processes, e.g. with regard to damage and friction.The challenges here arise in particular in ensuring a numerically robust process chain simulation.With the simulation model set up, the usefulness and sensitivity of the transmitted state variables are to be examined in an iterative process with regard to the overall process and with respect to the respective subsequent process steps.Furthermore, the entire process chain will be reproduced in detail by experiments, where geometry and material condition after each process step and the process variables will be determined as locally as possible and used to validate the simulation models. For this purpose, orientation-, temperature- and strain-rate dependent characteristic values of the joining parts, tools and fastener are to be measured. Challenges arise above all in the development of new investigation methods for the characterization of friction and damage to the joining materials under the complex boundary conditions in the mechanical joining process chain.In order to validate the established simulative process chain and the state variables, suitable sample forms must be developed which can pass through the entire process chain of joining part production, joining process and service phase and enable the targeted adjustment of the material state during joining part production (e.g. hardening, damage) in the area of the joining zone.The experimental detection of the material and geometric changes occurring in the process chain, which are essential for the validation of the process chain model and the material modelling concepts from other subprojects flowing into it, is a challenge.