各向异性刚度对轮胎力学特性及车辆操纵性的影响

Influence of anisotropic stiffness on tire mechanical properties and vehicle handling characteristics under combined slip situations

为揭示各向异性刚度值与轮胎力学特性的关系以及对复合工况车辆操纵性的影响规律,首先,通过引入方向因子描述复合工况总切力方向,提高了UniTire对复合工况轮胎力的建模精度;然后,根据轮胎试验数据分析了不同各向异性刚度值下轮胎力学特性变化规律,建立了考虑轮胎各向异性刚度值影响的有效侧偏刚度表达式;之后,建立了考虑轮胎各向异性刚度值影响的复合工况车辆操纵性分析模型,分析了轮胎处于不同各向异性刚度值时纵向加速度对车辆操纵性的影响;最后,通过CarSim软件平台对分析结果进行了仿真验证。结果表明:当轮胎各向异性刚度强时,复合工况下不同的制动/驱动模式对车辆的操纵性影响很小;当轮胎各向异性刚度弱时,复合工况下不同的制动/驱动模式会使车辆呈现出不同的操纵性。

In order to reveal the influence of anisotropic stiffness on tire mechanical properties and vehicle handling characteristics under combined slip situations. Firstly,the direction factor is introduced to describe the direction of resultant shear force in the contact patch,which improves the modeling accuracy of UniTire for combined slip tire forces;Secondly,the influence of anisotropy degree on tire mechanical properties is analyzed based on test data,and the expression of effective cornering stiffness considering the influence of tire anisotropy is constructed;Then a vehicle handling analysis model considering the influence of tire anisotropy is established,and the influence of longitudinal acceleration on vehicle handling characteristics is analyzed with different anisotropy values;Finally,the analysis results are simulated and validated with CarSim. The results show that with the strong anisotropy value, different braking/driving torque distribution modes have little effect on vehicle handling characteristics under combined slip situations.However,with the weak anisotropy value,the vehicle handling characteristics under combined slip situations are significantly affected by different braking/driving torque distribution modes.