Property-controlled process design of free-form bending considering material properties of the semi-finished product

The principal objective of the proposed research project, which spans over all three planned phases, is the development, flexibilization, and industrial implementation of a property-controlled freeform bending process. In addition to the control of workpiece geometry, its mechanical properties, e.g. strength, ductility, grain size distribution, and residual stress, shall be deliberately influenced during forming. This improved and more comprehensive control shall increase the quality and efficiency of the freeform bending process.The central innovative idea of this proposal is the development of a model-based closed-loop control system, which consists of process-parallel soft sensors and physical or empirical models. This system enables process monitoring before and after forming as well as control of mechanical properties which are difficult to register directly. Especially innovative is the model-based inline monitoring of mechanical material properties via force sensors at the bending instrument, acoustic emission sensors, and micromagnetic sensors. A further innovation of the proposed project is an adjustable heating of workpiece before the forming step and process integration into a robust monitoring and control system. These tasks require a cooperation of three applicants from the domains of material engineering, control theory and production engineering.The primary objective of the first phase is the demonstration of process controllability. It shall be done on a basis of a freeform bending machine in combination with a closed-loop control system and inline evaluation capabilities which shall be developed specifically for this project.