乘用车扩展移动性和跑扁轮胎轮胎刚度指数测试程序

[中文适用范围]： 本文件规定了测定乘用车轮胎的轮胎刚度指数的试验方法，对于能够为车辆提供基本轮胎功能的产品，至少在速度为 80 公里/小时（50 英里/小时）和行驶距离为 80公里 当在扁平轮胎运行模式下运行时，根据此方法旨在确定上述指数，用于通过其空气和结构部件来表征预期轮胎的刚度。 为了达到目标，需要测量不同操作条件下 Z 方向绝对位置意义上的垂直力和垂直偏转（在零充气压力的情况下为近似值），并通过本文件中定义的指标进行组合。 该方法不适用于传统轮胎。 [外文原描述]： ISO 19940:2017 specifies the testing method for determining the tyre stiffness index of passenger car tyres for the products capable of supplying the vehicle with the basic tyre functions, at least, at a speed of 80 km/h (50 mph) and a distance of 80 km when operating in flat tyre running mode, as per ISO 16992. This method is meant to determine the above mentioned index, for the characterization of the expected tyre's stiffness through its air and structural components. To reach the target, the vertical force and the vertical deflection, in the sense of absolute position in Z direction under different operating conditions, are measured (approximated in case of zero inflation pressure) and combined through the metrics defined in this document. This method is not intended to be used for conventional tyres.