SPP 1146:  Modelling of Incremental Forming Operations

• Subject Area: Mechanical and Industrial Engineering
• Term: from 2003 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5471839

Incremental forming operations are defined as those that produce required part geometries through a sequence of local impacts with simple tools rather than by a direct transmission of the tool shape to the workpiece (e.g. forging operations).The number of work cycles can range from several hundred (e.g. spinning or incremental sheet forming) to millions (e.g. shot peening). The complex forming history of these operations cannot be adequately described by analytical, nor by numerical methods at the present time. Consequently, the production process steps and the final product properties cannot be adequately predicted for an industrial operation. This has led to a discrepancy between the application of the incremental forming operations and the specific manufacturing capabilities of these processes.In incremental forming operations, very small plastic zones (as compared to the size of the workpiece) are created and often move through the part in a cyclic sequence of similar process steps, thus entailing unacceptable computational costs for finite element modelling. Further to that, there is a lack of sound constitutive models for materials undergoing cyclic forming operations.The primary goal of the Priority Programme is to develop the fundamental techniques for the efficient numerical modelling of incremental forming operations. This will be achieved through joint research in the fields of forming technology, applied mechanics and applied mathematics. The research will focus on the following key aspects:-- development of domain decomposition techniques to couple models with a high resolution (for the description of the process zone) with - if necessary - different, optimised models for a quick calculation of the elastic behaviour of the remainder of the workpiece (e.g. FEM/FEM coupling, FEM/BEM coupling, mortar methods) and combining these methods with fast iterative equation solvers (e.g. multigrid solvers);-- choice, implementation and experimental verification of thermodynamically consistent constitutive models for cyclic loading as well as the development of contact models and algorithms for incremental forming operations;-- technological investigations to develop adequate process models (e.g. the description of the complex tool kinematics, the determination of thermal and tribological boundary conditions) and to validate new simulation methods.

• DFG Programme: Priority Programmes
• International Connection: Ukraine

Projects

• A material model considering a substructure for the simulation of incremental forming processes (Applicant Kreißig, Reiner )
• Coupling of boundary elements and finite elements for incremental metal forming processes (Applicant Stephan, Ernst Peter )
• Der Einfluss technologischer Kenngrößen und Parameter auf den stationären Zustand beim Drückwalzen - Beschleunigung der FEM durch modifizierte Anfangswerte (Applicant Awiszus, Birgit )
• Development of a system for the simulation of plasma jet forming (Applicant Vollertsen, Frank )
• Effiziente Algorithmen zur Simulation von inkrementellen Umformverfahren (Applicant Schäfer, Michael )
• Effiziente Algorithmen zur Simulation von inkrementellen Umformverfahren (Applicants Groche, Peter ;  Schäfer, Michael )
• Entwicklung effizienter numerischer Simulationsalgorithmen für CNC-gesteuerte inkrementelle Umformverfahren (Applicant Wohlmuth, Barbara )
• Modeling of incremental massive forming (Applicant Franzke, Martin )
• Modellierung der Blechumformung durch eine Kombination verschiedener inkrementeller Verfahren (Applicant Hoffmann, Hartmut )
• Modellierung inkrementeller Blechumformprozesse mit kinematischer Gestalterzeugung (Applicant Tekkaya, A. Erman )
• Modellierung von Drückwalzvorgängen mittels FEM unter Ausnutzung der Gegebenheiten eines inkrementellen quasistationären Verfahrens (Applicant Besdo, Dieter )
• Modellierung von lasergestützten, inkrementellen Formgebungsprozessen an großen Blechformteilen (Applicant Otto, Andreas )
• Modellierung von Werkzeugbahnen für das Erzeugen prozessangepasster Platinen mittels eines Kraftformers (Applicant Hoffmann, Hartmut )
• Modelling of deep rolling thin-walled components (Applicant Klocke, Fritz )
• Modelling of incremental sheet metal forming (Applicant Hirt, Gerhard )
• Preconditioning of iterative solvers using hierarchical matrices (Applicant Bebendorf, Mario )
• Schnelle Randelementmethoden für inkrementelle Verformungen (Applicant Rjasanow, Sergej )
• Werkstoffverhalten bei inkrementalen Umformvorgängen (Applicant Meyer, Lothar W. )

• Spokesperson: Professor Dr.-Ing. Gerhard Hirt