Abstract: At present, virtual proving ground (VPG) is widely used because of its short development cycle and low cost. However, due to the certain difference between the multi-body simulation model and the actual model, the torque accuracy of the hard point can't be guaranteed, and the reliability of fatigue durability simulation based on the virtual proving ground is also unreliable. This paper selects the rear sub-frame and vehicle body as the research objects; extract the hard point load spectrum of the rear sub-frame and the vehicle body by VPG simulation; and use the torque and non-torque load spectrum for the fatigue durability simulation analysis respectively; compare and analyze the results of fatigue durability simulation analysis. The comparison results shows that the damage value ratio of fatigue durability simulation analysis by the torque and non-torque load spectrum is between 0.54～0.99. In general, the torque base on VPG has less influence of the result of fatigue durability simulation. Even though the torque accuracy can't be guaranteed, the overall results of fatigue durability simulation analysis will not be affected, which also proves that the fatigue durability simulation analysis based on VPG can be reliable.

Key words: Virtual proving ground; 3D digital road; Load spectrum; Torque; Fatigue durability

摘要： 目前虚拟试验场（VPG）因开发周期短、成本低而得到广泛运用，但由于多体仿真模 型与实际模型存在一定的差异，提取的硬点扭矩精度无法得到保证，故基于虚拟试验场的疲 劳耐久分析可靠性存在疑义。论文以后副车架和车身为研究对象，基于虚拟试验场路面提取 后副车架和车身的硬点载荷谱；分别以有扭矩和无扭矩载荷谱进行疲劳耐久仿真分析；对比 疲劳耐久仿真分析的结果。对比结果显示，有扭矩和无扭矩疲劳耐久仿真分析的损伤值比值 介于 0.54～0.99。总体而言，基于虚拟试验场的扭矩对疲劳耐久仿真的影响较小；在扭矩精 度无法保证的情况下，不影响疲劳耐久仿真分析的整体结果，从而也证明了基于虚拟试验场 的疲劳耐久仿真分析的可靠性。

关键词: 虚拟试验场；3D 数字路面；载荷谱；扭矩；疲劳耐久