Optical strain rate control in material characterization

Third Party Funds Group - Overall project


Start date : 01.02.2023

End date : 31.01.2025

Website: https://forschungsstiftung.de/Projekte/Details/Optische-Dehnratenregelung-in-der-Werkstoffcharakterisierung.html


Overall project details

Overall project

Optische Dehnratenregelung in der Werkstoffcharakterisierung

Project details

Short description

By improving the accuracy with which material behavior is represented in simulations, components and manufacturing processes can be designed more resourceefficiently. Thus, material characterization  plays a central role in the implementation of new lightweight design strategies and the achievement of better vehicle crash behavior.
A fundamental knowledge of material behavior is necessary for the targeted forming of metallic materials. Characterization tests, such as the tensile test, are used to determine specific material parameters such as yield stress, tensile strength, uniform elongation and elongation at break. In addition, the elastic-plastic material behavior can be analyzed. Through the appropriate choice of a material model, this material behavior is mapped in a simulation. Formingsimulations represent the manufacturing process and are used for the design of tools and sheets and contribute to the safe and resource-saving design of parts.
Most metallic materials exhibit strain rate sensitivity. This means that the material behavior changes depending on the forming speed. In particular, quasi-static characterization tests carried out at low strain rates, which hardly ever occur in real forming processes, lead to deviations from the real material behavior. Thus, the consideration of the actual strain rate sensitivity leads to an improved material modeling and thus simulative representation of the material behavior.
The aim of the research project is therefore to develop, in cooperation with the project partners, a robust method for carrying out optically strain-rate-controlled tests and to analyze the influence on the prediction quality of simulations. This will reduce the difference between the nominally selected strain rate and the actual strain rate. By this method, more accurate material parameters are measured, which in turn enables an improved component and process design.

Scientific Abstract

By improving the accuracy with which material behavior is represented in simulations, components and manufacturing processes can be designed more resourceefficiently. Thus, material characterization  plays a central role in the implementation of new lightweight design strategies and the achievement of better vehicle crash behavior.
A fundamental knowledge of material behavior is necessary for the targeted forming of metallic materials. Characterization tests, such as the tensile test, are used to determine specific material parameters such as yield stress, tensile strength, uniform elongation and elongation at break. In addition, the elastic-plastic material behavior can be analyzed. Through the appropriate choice of a material model, this material behavior is mapped in a simulation. Formingsimulations represent the manufacturing process and are used for the design of tools and sheets and contribute to the safe and resource-saving design of parts.
Most metallic materials exhibit strain rate sensitivity. This means that the material behavior changes depending on the forming speed. In particular, quasi-static characterization tests carried out at low strain rates, which hardly ever occur in real forming processes, lead to deviations from the real material behavior. Thus, the consideration of the actual strain rate sensitivity leads to an improved material modeling and thus simulative representation of the material behavior.
The aim of the research project is therefore to develop, in cooperation with the project partners, a robust method for carrying out optically strain-rate-controlled tests and to analyze the influence on the prediction quality of simulations. This will reduce the difference between the nominally selected strain rate and the actual strain rate. By this method, more accurate material parameters are measured, which in turn enables an improved component and process design.

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Funding Source