关键词: 商用车；前下防护；结构设计优化；轻量化；有限元分析

Abstract: As a core component of the passive safety system of commercial vehicles, the traditional front underrun protection structure has difficulties and problems such as easy fracture of connecting bolts, limited design space, and structural instability, which urgently need to be optimized. This paper proposes a new front underrun protection structure for commercial vehicles. By optimizing the key connection points of the structure, the load path of the entire structure is changed to prevent the connecting bolts from bearing excessive forces. At the same time, lateral support structures are added on both sides to withstand collision impact forces from multiple directions and improve the stability of the cross member. Additionally, lightweight design is applied to the cross member by using an aluminum alloy structure, which enhances the energy absorption capacity of the cross member and reduces the load on the connecting brackets. Combined with computer-aided engineering (CAE) analysis, the new structure's ability to withstand impact forces from a collision meets regulatory requirements, and the structure does not experience instability.

Key words: commercial vehicle; front underrun protection; structural design optimization; lightweight;finite element analysis