越野车前轴转向节结构设计与有限元分析

Finite element analysis and structural optimization of steering knuckle for off-road vehicles

在一款越野车研发中,为了设计出满足强度要求的越野车转向节,提高其工作可靠性,应用CAXA软件建立转向节的三维实体模型,通过对转向节进行受力分析,分别研究了转向节在三种典型危险工况(越过不平路面、紧急制动和侧滑)下的受力情况,利用Patran/Nastran对转向节进行有限元分析,分析和研究了转向节在三种典型危险工况下的应力分布情况,根据分析结果对转向节进行结构改进,改善了其受力情况。结果表明:该转向节在轴与转向节体连接处、转向节轴阶梯过渡处存在应力集中,在侧滑工况下达最大值759 MPa,不满足强度要求,需对结构进行进一步的改进。通过将转向节体与轴联接处圆角半径由1 mm增大至3 mm,将转向节轴过渡处采用锥面过渡,得出通过过渡部分的改进可以减少应力集中,改进后转向节过渡处侧滑工况下最大应力降为657 MPa,强度提高了13.4%。研究结果为有效的提高转向节在工作时的强度提供了量化依据。

In order to design a steering knuckle with enough strength and reliability for research and development of an off-road vehicle, three-dimensional model of steering knuckle is established by CAXA. The forces of steering knuckle working under three typical dangerous conditions, such as uneven road, emergency braking and side-slip were studied. Finite element analysis of steering knuckle was carried out by Patran/Nastran, and the stresses of steering knuckle under three typical dangerous conditions were analyzed and studied. The structure and stress condition of steering knuckle was improved. The research results showed that the stress concentration occurs in connec-tion with shaft and body of steering knuckle, the maximum stress reached 759 MPa in the siding＆amp;nbsp;condition, does not meet the strength requirements, and the structure of steering knuckle need fur-ther improvement. It is concluded that the stress concentration can be reduced through the improve-ment of the transition section, increasing the radius of the shaft and body connection to 3 mm（ origi-nal size is 1 mm） , and using cone transition at the shaft transition. The maximum stress of the im-proved steering knuckle reduced to 657 MPa in the siding condition, and the strength of steering knuckle increased by 13. 4%. The results provide a quantitative basis for improving the strength of steering knuckle.