Multiscale modelling of joining processes taking account of the thermomechanical-chemical behavior in the boundary layer

连接过程，如这里所考虑的辊压焊，冷锻和铆接过程，其特征在于塑性变形和热机械耦合效应的复杂相互作用。此外，必须考虑过程中涉及的微观结构之间的相互作用。新的或改进的连接技术的设计需要对机理有基本的了解，而这仅仅通过实验是难以实现的。因此，本项目涉及一个健全的多尺度建模的基本效果，特点加入。该项目的重点是连接强度和多材料接头的力学性能。我们区分微观尺度建模，它允许过程独立的调查的物理过程中发生的连接，和宏观力学建模的一部分，考虑到具体的过程中的结构特征。这里的重点是尽可能准确，但规模足够的分辨率的界面中的热机械行为，这是要实现的显着扩展的内聚区技术。宏观力学建模将通过一个数据库进行，该数据库是在微观尺度详细参数研究的基础上生成的，并由伙伴项目和本项目的实验数据加以补充。微观和宏观力学工艺参数对连接的影响必须在每个建模尺度上精确捕获。该研究项目的最终目标是开发一种功能强大的新模拟工具，能够预测不同连接过程的结果。此外，它应允许选择一个合适的连接过程中的要求，这些过程中的鲁棒性和再现性的定义组合，而不需要额外的实验研究。

Joining processes, such as the here considered processes of roll bonding, cold forging and clinching, are characterized by a complex interaction of plastic deformation and thermomechanical coupling effects. Additionally the interactions between the microstructures involved in the process have to be taken into account. The design of new or improved joining technologies requires a fundamental understanding of the mechanisms which is difficult to achieve by working solely experimentally. The present project therefore deals with a sound multiscale modelling of the essential effects characterizing joining. The emphasis of the project is on the joint strength and the mechanical properties of multi-material joints. We distinguish between microscale modelling which allows the process-independent investigation of the physical processes taking place during joining, and the macromechanical modelling part which takes the structural characteristics of concrete processes into account. The focus is here on the as accurate as possible but scale adequate resolution of the thermomechanical behaviour in the interface which is to be achieved by a significant extension of the cohesive zone technique. The macromechanical modelling is to be developed by means of a database that is generated on the basis of detailed parameter studies at the microscale and is complemented by experimental data from partner projects and the present project. The influence of the micro- and macromechanical process parameters on joining must be precisely captured at each modelling scale. The final objective of the research project is to develop a powerful new simulation tool that enables the prediction of results of diverse joining processes. Furthermore, it shall allow the choice of a suitable joining process for defined combinations of requirements, among these robustness and reproducibility of the process, without the need of additional experimental investigations.