矿用自卸车行驶道路恶劣且载重量大，严重影响了行驶平顺性，而油气悬架的力学特性对改善整车平顺性有着重要作用。为研究和优化悬架力学特性，在考虑悬架快速加载和油液通道的附加阻力、进口局部阻力、弯道阻力的基础上，建立精确的弹性力和阻尼力公式。利用Fluent软件结合Volume of Fluid两相流模型和动网格技术，仿真得到油气悬架非线性力学特性，以对比推导的力学公式。此外，在悬架力学公式的基础上，建立包含柔性化车架的整车刚柔耦合模型，并将模型仿真结果与试验结果进行对比，得到座椅加速度响应最大误差为8.5%，验证了所建模型的准确性。采用遗传算法对悬架参数进行优化，座椅加权加速度方均根值降低了23.58%，有效提高了矿用自卸车的平顺性。

Mining dump truck with heavy loads drives on the rough roads, which affects the riding comfort seriously, and the mechanical property of hydro-pneumatic suspension plays an important role in improving the riding comfort. In order to research and optimize suspension mechanical property, the accurate formulas of elastica and damping are established in consideration of the rapid loading, additional and local resistance. Fluent is used to combine volume of fluid model and dynamic grid technique to compare the derived mechanical formulas by simulating the mechanical property. In use of the mechanical formulas, the coupled multi-body dynamics model of this truck, containing flexible frame, is built, and the model is verified by the test data, on account of the maximum error of the seat acceleration up to 8.5%.The suspension parameters are optimized by genetic algorithm, the root mean square of the seat acceleration reduces by 23.58% after optimization, the dump truck’s riding comfort is improved obviously.