7.50R20 14PR PW02型轮胎侧偏刚度的试验与拟合

为给使用某公司产7.50R20 14PR PW02型轮胎车辆的操纵稳定性研究提供准确的轮胎侧偏力计算公式,对该轮胎进行了相关试验与数值拟合。首先,在标准胎压下就5种不同载荷,测量了侧偏角范围-8°～8°内对应的侧偏力。然后使用MagicFormula模型及Unitire模型分别对该轮胎侧偏刚度进行了数值拟合,并就使用Unitire模型在数值拟合的过程中Ey(侧向力曲率因子)及μy(侧向摩擦系数)的部分拟合值超出取值定义域的现象给出了相关修正方法。最后对上述拟合结果与试验数据进行了对比分析,结果显示:使用Magic Formula模型得到的侧偏力计算公式的计算精度较高,其最大残差仅为0.68%,说明7.50R20 14PR PW02型轮胎对Magic Formula轮胎模型较适应。

Testing and Numerical Fitting of Cornering Stiffness of 7.50R20 14PR PW02 Tire

To provide a precise expression for cornering force in research on handling stability of vehicle equipped with one of 7.50R20 14PR PW02 tire,testing and numerical fitting of cornering stiffness of the 7.50R20 14PR PW02 tire are carried out.Firstly,cornering forces according to slip angles that range from-8° to 8° in five kinds of tire loads are tested under nominal tire pressure.Secondly,Cornering Stiffness of the 7.50R20 14PR PW02 tire is numerical fitted based on two kinds of tire models,Magic Formula one and Unitire one,and a correcting method is proposed according to some fitting values beyond definition domains of Ey(sideway force curvature factor)and μy(sideway friction factor).Finally,it is shown that a high evaluating precision can be obtained by cornering force's evaluating expression from Magic Formula model and maximum fitting residual is only 0.68%,so the 7.50R20 14PR PW02 tire is suitable for Magic Formula model in comparative analysis from numerical fitting data to testing data.