Multi-Objective Satisfactory Design Solution Sets for Designing a Maximum Crash-Worthy Cabin Section Shape Using Preference Set-Based Design

摘要

In the early design period of vehicle development, topology design contributes greatly determining the section shape and topology of the main structures for achieving multi-objective performance. Veteran engineers' experience-honed skill is responsible for the topology design in the early design period, section shape and layout of the main structures, via topology design, being dependent on this skill. Generally, the engineers develop the section of main structures in a vehicle for crashworthiness performance by analyzing plastic moment (Mp) and all plastic axial tension in the early design period of vehicle development. The condition for estimating plastic deformation is based on the amount of plastic deformation in the section of the structure. However, the threshold of the deformation phenomenon in crash testing differs from the threshold of the phenomenon for analyzing the plastic moment (Mp). Therefore, we propose that the development method for deciding the optimum section shape for vehicle crashworthiness performance be the shape rigidity of the section using Preference Set-based Design (PSD). In this study, the PSD method was applied to the development of the floor member of a heavy duty truck cabin. Adopting PSD gave us the optimum section shape of the main floor member, which achieved multi-objective crashworthiness performance, without much trial and error. Also the optimum section shape results in an 18% weight reduction, compared to the current section shape. Finally, we found that this proposed development method, considering the shape rigidity of section, can give us the optimum section shape, which simultaneously and efficiently, achieved multi-objective performance goal, in comparison with the previous method for determining the section shape for plastic deformation.