The application of mechanical joining technology offers the possibility of joining mixed structures with a wide range of specifications and material-geometry combinations. Due to the limited transparency of the processes externally, the high number of combinable tool variants as well as variable force- and stroke-based process parameters, a comprehensive validation of the joinability in versatile process chains along the process steps is not possible with a conventional, experiment-based approach.
The vision of the subproject is therefore the development of methods for the holistic prediction of the joining safety, joining suitability and joining possibility along the versatile process chain. For the necessary comprehensiveness with regard to the joining part materials, joining processes and operating conditions, in addition to the development of methods, already developed methods of other subprojects of the TRR are integrated in TP A01. Combined methods from experimental test methods and simulation models, which describe the joint behavior on the basis of the material behavior, will be developed in order to open up fundamental operating principles and to enable comprehensive prediction on the basis of simulation. Finally, the methods will be used to develop targeted flexibilization and robustification measures for versatile process chains against the varying input variables.
In TP A01, a simulation strategy is being developed that virtually maps the process steps of joining part production, joining process and loading phase and allows the relevant state variables, such as geometry, material hardening and damage, to be transferred for a continuous simulation of mechanical joinability. The simulation model is to be used in an iterative process to investigate the usefulness and sensitivity of the transferred state variables with regard to the overall process and to the respective subsequent process steps. For the validation of the simulation models, the entire process chain will be reproduced experimentally in detail, with geometry and material condition being determined as locally as possible after each process step, as well as the process variables. This requires the development of new test methods for characterizing the frictional properties and damage behavior of joining part materials under the complex boundary conditions of the process chain. In addition, suitable specimen forms must be developed which can run through the entire process chain and allow targeted adjustment of the material condition during joining part production in the area of the joining zone as well as combined loading conditions.