Multi-Objective Topological Optimization of an Electric Truck Frame Based on Orthogonal Design and Analytic Hierarchy Process

Jie Qiao,Yongtao Liu,Suo Zhang,Kunying Wu,Fengxiang Xu

doi:10.1109/access.2020.3012878

Abstract

The electric truck frame as a vital load-bearing component has aroused growing attentions due to its enormous potential in lightweight. However, few systematic studies have been performed on the multi-objective topological design of the frame attributable to its complexity on loading and conflicting objectives. This paper aims to develop a multi-objective topology optimization strategy of the electric truck frame based on the hybrid decision making method combining orthogonal test design (OTD) and analytic hierarchy process (AHP). The hybrid strategy is performed to obtain a new set of weight ratio combination from objective data and subjective judgment. The topological results show that the overall performance of the optimal frame is better than any of the methods applied alone. By comparing, it is found that the strength and stiffness of the optimal frame is higher than that of the original frame from the perspective of static conditions, and the low-order natural frequency of the optimal frame is significantly improved. It demonstrates that the proposed approach could be as an effective tool for multi-objective topology optimization of the electric truck frame in seeking lightweight and comprehensive mechanical performance. The hybrid strategy might be expected to provide some guidance for more complicated engineering problems.

Highlights

The frame subjected to various conditions such as bending and torsion during driving is the main load-bearing component of the whole vehicle, thereby it has aroused extensive research in term of the desirable balance between performances and lightweight [1]–[3]
This paper aims to develop a topology optimization strategy of dynamic electric truck frame based on orthogonal test design (OTD) and analytic hierarchy process (AHP)
SINGLE-OBJECTIVE TOPOLOGY OPTIMIZATION The minimum mean compliance is the objective function of stiffness (Eq (1)) and the maximum average frequency is taken as the objective function of the characteristic frequency (Eq (3))

Summary

Introduction

The frame subjected to various conditions such as bending and torsion during driving is the main load-bearing component of the whole vehicle, thereby it has aroused extensive research in term of the desirable balance between performances and lightweight [1]–[3]. J. Qiao et al.: Multi-Objective Topological Optimization of an Electric Truck Frame minimum mean-compliance of multi-conditions under and maximize eigenfrequency under dynamics [5], [6]. For the multi-objective optimization problem, the classical method is to transform the multi-objective problem into a single-objective problem by linear weighted sum method. This method is simple to calculate, it is quite difficult to solve all Pareto optimal solutions for nonconvex optimization problems [7], [8]. A multi-objective topology optimization method based on compromise programming theory has been widely used by researchers [9]–[11]. It might be unreasonable for designers to directly assign values for weights because of the uncertain, incomplete, and local properties inherent to weights themselves [12]

Objectives

Results

Conclusion