某大型运输车的耐久性虚拟试验研究

耐久性问题是车辆领域的研究热点，对车辆进行实物疲劳实验成本高、周期长，为了缩短研制周期，降低研究成本，提出了虚拟试验的方法来研究车辆的耐久性问题. 以某大型运输车为研究对象，建立了其有限元模型，通过静力学分析获取了应力分布结果和车架变形结果；通过模态分析获取了柔性体结构的模态信息. 基于模态应力恢复理论，考虑车架、上摆臂、下摆臂和力轴的柔性，建立了整车刚柔耦合模型，获取了在平坦路面行驶的动力学响应.与实测结果对比，车架测点的垂向加速度均方根值在误差接受范围内，验证了模型的正确性. 根据Palmgren-Miner准则，对车辆在D级路面的行驶寿命进行了评估，结果表明，4桥悬架结构疲劳寿命最小，并且下摆臂结构出现了应力集中. 通过改进下摆臂结构增加了其使用寿命，为车辆结构的设计提供了参考. 

Virtual Research on Durability of Large Special Freight Vehicle

Durability is a research hotspot in the field of vehicles. The physical fatigue test on vehicles is costly and time-consuming. In order to shorten the development cycle and reduce research costs, a virtual test method was proposed to study the durability of vehicles. Firstly, a finite element model was established for a research object of a large special freight vehicle, and the results of stress distribution and frame deformation were obtained through static analysis; the modal information of the flexible body structure was obtained through modal analysis. And then, based on the modal stress recovery theory, considering the flexible body of the frame, upper swing arm, lower swing arm and force axis, a rigid-flexible coupling model of the whole vehicle was established, and the dynamic response of driving on a flat road was obtained. Compared with experiment results, the root mean square value of the vertical acceleration at the measuring point of the frame is in acceptable range, validating the correctness of the model. Finally, according to the Palmgren-Miner criterion, the driving life of the vehicle was evaluated on grade D roads. The results show that the fatigue life of the 4 axle suspension structure is the smallest, and the lower swing arm structure has obvious stress concentration. An improved lower swing arm structure can increase its service life, providing a reference for the design of vehicle structure.