Fine blanking of carbon fibre reinforced plastics (fine blanking CFRP)

• Applicant: Professor Dr.-Ing. Thomas Bergs
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 452410572

Carbon fibre reinforced plastics (CFRP) demonstrate a high strength to density ratio as compared with the conventional construction materials. This material property of CFRP provides a high potential for the manufacturing of the weight-optimized components in the contest of material based lightweight design. CFRP components are manufactured near-net-shape. However, in order to fulfill geometrical or functional requirements, CFRP components have to be finish processed. Finish processing entails trimming of the outer contour or manufacturing of holes. One potentially economically efficient and productive manufacturing technology for the finish processing of CFRP components is fine blanking. Fine blanking of CFRP does not belong to the state of the art. The effects of the material and process parameters of fine blanking on the resulting process forces and quality parameters of the fine blanked CFRP components have not been researched yet.The objective of this project is the identification and explanation of process specific material separation mechanisms in fine blanking of CFRP on the basis of experimental numerical investigations. In the first phase of the proposed project, the fine blanking of unidirectional CFRP laminates from high tenacity fibers is investigated as a function of different relative fiber volume fractions. The gained basic understanding will then enable a targeted process design of fine blanking for the manufacturing of CFRP components with high quality, taking into account the investigated material parameters. In the second project phase, the gained basic understanding will be extended by fine blanking of unidirectional CFRP laminates under consideration of different carbon fiber types. The aim is to transfer the overall findings to the fine blanking of multidirectional CFRP laminates.In order to achieve the objective of the first project phase, experimental investigations on unidirectional CFRP laminates are conducted under variation of the material parameter relative fiber volume fraction as well as the process parameters of fine blanking. By these means, significant cause and effect relationships between the analyzed parameters and the process resulting cutting forces as well as the quality parameters of fine blanked CFRP components are identified. Simultaneously, a numerical process model of CFRP fine blanking based on the finite element method is developed and validated with the experimental data. Subsequently, the generated experimental and numerical results will be synthesized to a physically based explanation model regarding the separation mechanisms during the fine blanking of CFRP. Finally, the explanatory model of the separation mechanisms is validated based on fine blanking tests.

• DFG Programme: Research Grants