Creation of a parametric optimization process for an eAxle gear body using open-source tools

This master’s degree Thesis deals with the optimization of the solid body of a Gear in an eAxle transmission, using an automated process based on Finite Element Analysis. This activity was performed at Dumarey Automotive Italia S.p.A. The company has already developed such an optimization process for this component, using commercial tools. Its goal is to achieve a mass reduction, without penalizing the structural strength. Due to the cost of the commercial tools and the high number of cases to be simulated, such an optimization procedure represents a significant financial burden. The aim of this Thesis is the development an equivalent process using open-source tools, as a valid alternative. A preliminary activity was the study of the involved component and the analysis of the existing procedure, including the discovery of the commercial tools to understand their specific role in the process. For this thesis, the global process of simulation has been divided in two main parts: automation and optimization. The automation part is responsible for performing the simulation of a single geometric configuration of the gear to obtain its mass and the associated stress. The automated process should be understood as a tool for the optimization part. An algorithm will test many configurations to provide a set of optimized gear designs. Automation and optimization are complex task and consist of many subtasks which can be associated to specific software families. As a mandatory piece of optimization, the automation process was the first to be developed. For each subtask of the automation, the approach was the same. First, find the proper open-source tool. It was important to consider the features of the tool to properly replace the commercial ones, the possibility of automating tasks within the software and finally keep in mind that the different software will work together to form a global automated process. Before going beyond with the software, it was preliminary validated by comparing its results to the commercial equivalent. Once a software was approved, a programming activity was performed to replace the manual operations by automated scripts. After all the subtasks were successfully completed, an additional programming activity was necessary to create the global process, which can be seen as a black box. This black box starts from a geometrical set of parameters for gear body, creates the corresponding geometry, mesh, performs its simulation, and then returns the expected results. To be fully automated, this process should operate without any human interaction. Once the automated black box was operational, the focus shifted to the creation of the optimization process. Also in this case, first goal was the selection of the proper open-source tool, capable of providing an appropriate algorithm for the optimization, similar the one used in the commercial tool. Then, the challenge was to link the algorithm to the automated process, making the optimization tool able to give data to the black box and receive the individual results. With these results, the algorithm can optimize the geometrical configuration. The final task of this thesis was to perform the optimization, then analyse and comment the obtained results. Next step of the activity for Dumarey Automotive Italia S.p.A., will be to reproduce such an approach and extend the process to other mechanical components.