Fiber Beads: Development of a numerical method for the synthesis of fiber-reinforced bead patterns
Engineering Design, Machine Elements, Product Development
Primary Shaping and Reshaping Technology, Additive Manufacturing
Final Report Abstract
In the DFG research project "Fiber Beads", the integration of hybrid material beads in sheet metal components was investigated as a method for lightweight design applications. This is achieved by a local integration of unidirectional, carbon fiber-reinforced plastic (UD-CFRP) on the top flange area of the beads. The aim was to further increase the component stiffness in relation to the component mass and to improve manufacturing flexibility compared to established strategies for bead insertion. For a demonstrator component, the design and experimental implementation of a multi-stage manufacturing process chain was realized. In addition, a numerical optimization tool was developed for component design. The manufacturing process chain was designed with a focus on its applicability in an industrial environment. It consists of the steps of sheet metal forming, surface pre-treatment and surface structuring in combination with the application and curing of the UD-CFRP reinforcement patches. Active tool elements additively manufactured from an elastomer material were investigated for the forming of adapted bead cross-sections. Sandblasting and laser structuring were implemented as surface structuring methods characterized by short process times. Robot-based Automated Fiber Placement (AFP), a method suitable for high-volume production due to a high degree of automation, was selected for the attachment of the reinforcement patches. To support the product development process, a computer-aided optimization method was developed by which the optimal position and the local degree of reinforcement for stiffness maximization can be determined for specific load cases. For this purpose, a substitute model was developed for robust optimization based on a detailed model from a deep-drawing simulation, which uses material parameter sets to map different degrees of reinforcement. This allows a sufficiently similar structural-mechanical behavior to be mapped. Using the implemented algorithm, the assignment of the parameter sets can be adjusted iteratively in order to determine a stiffness-optimized reinforcement pattern. In an extension of the optimization method, a procedure for determining a basic component with load case-specific variants was developed. By placing the reinforcement in the top flange area of the beads, a significant increase in the area moment of inertia and the bending stiffness can be achieved applying a small amount of UD-CFRP. In addition, the unidirectional fiber orientation allows to take advantage of the anisotropic properties of the composite material. These aspects promote the most economical use of the UD-CFRP material for the flexible production of load-adapted product variants.
Publications
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A Method for Deriving a Substitution Finite Element Model of Fiber-Reinforced Beaded Sheet Metals, NAFEMS World Congress 2021
Haberkern, P.; Ott, M.; Volk W. & Albers A.
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An approach to validate simulation models for the optimization of fiber-reinforced bead patterns. NAFEMS Deutschland, Österreich, Schweiz GmbH (Hg.): Conference Proceedings NAFEMS Seminar: Integration of Simulation and Test in Product Development
Haberkern, P.; Ott, M.; Volk, W. & Albers, A.
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Load-specific variant generation of bead cross sections in sheet metal components by unidirectional carbon fibre reinforcement. IOP Conference Series: Materials Science and Engineering, 1157(1), 012093.
Ott, M.; Haberkern, P.; Gruber, M.; Hartmann, C.; Risch, T.; Wunderling, C.; Albers, A. & Volk, W.
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Optimization of fiber-reinforced bead patterns using an evolutionary algorithm. WCSMO-14
Haberkern, P.; Ott, M.; Volk W. & Albers A.
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Einfluss der Variation von Parametern eines evolutionären Algorithmus auf die Optimierung von faserverstärkten Sickenmustern, Munich Symposium on Lightweight Design 2022
Haberkern, P.; Ott, M.; Volk, W. & Albers, A.
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Experimental Investigation of Factors Influencing the Determination of the Onset of Yielding by Temperature Measurement. Key Engineering Materials, 926, 1021-1029.
Vitzthum, Simon; Gruber, Maximilian; Rebelo-Kornmeier, Joana; Hofmann, Michael & Volk, Wolfram
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Numerical and experimental investigation on the applicability of elastomer tooling components for the manufacturing of undercut geometries by sheet metal forming. Materials Research Proceedings, 25, 289-296. Materials Research Forum LLC.
Ott, M.
