TRR 188:  Damage Controlled Forming Processes

Subject Area Mechanical and Industrial Engineering
Construction Engineering and Architecture
Materials Science and Engineering
Term since 2017
Project identifier Deutsche Forschungsgemeinschaft (DFG) - Project number 278868966
 

Project Description

Forming processes enable the realization of cost- and resource-efficient components with outstanding mechanical properties. Yet, conventional design approaches do not take ductile damage into account. The overarching goals of the TRR are thus: to identify damage in formed metallic parts; to control them during forming; and to predict their effect on performance during service. Moving from formability to usability will be a paradigm shift in metal forming. The integral pillars of the TRR are three research areas: Process Technology (A), Characterization (B), and Modeling (C). New characterization methods from B enable the evaluation of formed components from A, with the parameter identification and model development from C. Three industrial transfer projects were started, and more are in preparation emphasizing the industrial relevance. In the first two funding periods, it has been shown that it is possible to control damage in sheet and bulk forming processes. Understanding the microscopic damage mechanisms, the local damage evolution as a function of process parameters can be predicted with physics-based modeling and simulation. Significant performance improvements have been achieved, mainly by adjusting the load path during forming towards negative stress triaxiality and by including the deviatoric influence. Thermal mechanisms affect damage too, in both hot forming and in subsequent heat treatments in cold forming. A damage-tolerant microstructure for DP800 has been identified for semi-finished products. In the upcoming 3rd funding period, the paradigm shift will be completed. Advanced phenomena (e.g., void closure and healing, cyclic loading, phase transformations) will be addressed; the complexity of forming processes will be increased beyond rolling, cold forging, bending, and deep drawing by including incremental forming, hydroforming, and elevated temperature forming; press hardening of 22MnB5 steel will stay in focus; a stainless steel without additional heat treatment will be analyzed in warm forging. The material spectrum will be extended to aluminum AA6010 and 6082, as different damage mechanisms are expected in these light alloys. Besides the commercially-available materials, steels with self-designed and manufactured damage-resistant microstructures will remain paramount. The next generation of damage models including void morphology, healing, and heat treatment will be created, together with enhanced data-based prediction of damage and the necessary parameter identification. Finally, the knowledge about damage will be utilized in the design of components, exemplified by demonstrators. Coupling of forming-induced and in-service damage (e.g., impact, fatigue) will be realized. Systematic analysis of the uncertainty and sources of scatter along the whole process chain will support this effort. Successful completion of the 3rd funding period will enable the resource-efficient design of lightweight .components near their limits
DFG Programme CRC/Transregios

Current projects

Completed projects

Applicant Institution Technische Universität Dortmund, since 1/2025
Business and Industry Karlsruher Institut für Technologie, since 1/2025
Co-Applicant Institution Rheinisch-Westfälische Technische Hochschule Aachen
Spokespersons Professor Dr.-Ing. Gerhard Hirt, from 1/2021 until 6/2023; Professor Yannis Korkolis, Ph.D., since 1/2025; Professor Dr.-Ing. A. Erman Tekkaya, from 7/2023 until 12/2024