Structural optimization for weight reduction of a tractor front-axle support

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Source: iChrome

Leading tractor manufacturer Same Deutz-Fahr used iChrome’s Nexus optimization and process integration software and Shaper 3D mesh morphing tool to achieve weight reductions together with an overall performance increase in complex 3D assemblies in its products. In this project, the key objective was to improve the initial shape of a tractor front-axle support, with the goal of minimizing the overall weight under performance requirement constraints.

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Flange details—initial (left) and optimized (right) solution. Source: iChrome

Methodology—With Shaper, parameterization can be defined directly on the finite element model, and the new configuration can be immediately obtained by morphing the original mesh. The optimization process can then be integrated with any external finite element solver using Nexus, and the whole procedure can be completely automated, yielding substantial reductions in schedule and design costs. In this project, these techniques were used to optimize the thickness and overall dimensions of the tractor front-axle support in order to reduce the mass of the component. Constraints on structural performance were taken into account during the optimization process.

The design space was partitioned over different sections to correctly define the morphing parameters. Structural optimization was performed using Nexus, starting from an initial design of experiments based on optimality criteria. Structural performance was evaluated via the Nastran direct-integration node in Nexus.

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Optimized stress contour. Source: iChrome

Results—Overall weight was reduced 15% compared with the previous design. The optimized solution maintained stress and global displacement levels under the allowed limits by significantly reducing the size of the lateral flanges and reinforcements where lower stress levels were detected, and by efficient reshaping of the higher-stress regions.

Benefits of using Nexus in this project included easy integration of external solvers; accurate 3D morphing using advanced nonlinear techniques that preserve the original quality of the mesh; parallel and concurrent evaluations to fully utilize available hardware and software resources; access to all results via organized tables and SQL external databases; advanced DOE and statistical tools to explore and analyze results; and state-of-the-art libraries for single optimization leading to the optimal solution.

Reference: A. Cervasio, F. Galli, M. Mariani, “Optimization of Tractor Front-Axle Support by Means of Advanced 3D Mesh Morphing,” Analisi e Calcolo, December 2014.