The wet grip performance of tire is one of the important performances affecting vehicle safety. The steering, acceleration, and braking of the vehicle are directly affected by the grounding characteristics between the radial tire and the ground. In order to study the influence of grounding characteristics of the tire on wet grip performance, ten 205/55R16 tires produced by different manufacturers were selected and tested. The grounding characteristics of the tires were tested using an optical test rig for tire grounding pressure distribution, considering inflation pressure distribution, load and wheel alignment. The tire-road contact area was subdivided into five parts, and 69 parameters were used to describe the grounding characteristics. A software was proposed to process the test results automatically, and 69 grounding characteristic parameters of each tire were obtained. Correlation analysis on tire wet grip performance and grounding characteristics was used for selecting the principal parameters. Finally, eight grounding characteristic parameters related to tire wet grip performance was obtained. Among them are five grounding characteristic parameters (central area rectangle ratio, central area width, internal shoulder length-to-width ratio, external and internal shoulder contact area ratio, external and internal shoulder impression area ratio) which have high correlation to tire wet grip performance, and three grounding characteristic parameters (external shoulder width, external shoulder length-to-width ratio, external and internal shoulder width ratio) which have low correlation to the wet grip performance of the tire. The principal component analysis method was used to analyze the highly correlated grounding characteristic parameters, and the regression equation for evaluating tire wet grip performance was fitted. The comparison of experimental and fitted values show that the errors are within 4%. The result demonstrates that, the method for evaluating wet grip performance of the radial tire through tire-road grounding characteristics was achieved.

轮胎的湿抓地性能是影响车辆安全性的重要性能之一。子午线轮胎与地面之间的接地特性直接影响车辆的转向，加速和制动。为了研究轮胎的接地特性对湿抓地性能的影响，选择并测试了十个由不同制造商生产的205 / 55R16轮胎。考虑到充气压力分布，负载和车轮定位，使用光学测试仪对轮胎的接地特性进行了测试，以了解轮胎的接地压力分布。将轮胎与地面的接触区域分为五个部分，并使用69个参数来描述接地特性。提出了一种软件来自动处理测试结果，获得每个轮胎的69个接地特性参数。使用轮胎湿抓地性能和接地特性的相关分析来选择主要参数。最后，获得了与轮胎湿抓地性能相关的八个接地特性参数。其中有五个接地特征参数（中心面积矩形比，中心区域宽度，内部肩长宽比，外部和内部肩部接触面积比，外部和内部肩部印痕面积比）与轮胎湿抓地力具有高度相关性性能和三个接地特性参数（外部胎肩宽度，外部胎肩长宽比，外部胎肩和内部胎肩宽比）与轮胎的湿抓地性能之间的相关性较低。使用主成分分析法分析高度相关的接地特性参数，并拟合用于评估轮胎湿抓地性能的回归方程。实验值和拟合值的比较表明，误差在4％以内。结果表明，实现了通过轮胎-道路接地特性评价子午线轮胎的湿抓地性能的方法。