【摘要】 制动试验台测试的摩擦系数不确定度决定测量结果有效与可靠性。基于缩比制动试验台，在制动压力2.89 kN及50～160 km/h制动速度条件下，针对铜基粉末冶金闸片，分别采用GUM、MCM法对摩擦系数的不确定度进行评定。结果表明:GUM法计算的不确定度为0.0057～0.0061,MCM法计算的为0.0045～0.0053，前者评定结果较后者高7%～25%。原因在于GUM法计算是假定输入量为正态分布，摩擦系数的波动性导致数据样本偏离正态分布，起到增大不确定度的作用。MCM法计算采用的输入量是按概率分布考虑，减少偶然数据的作用。因此，对于缩比制动试验台的摩擦系数，以MCM法不确定度评定结果为宜。更多还原

【Abstract】 To address the issue of validity and reliability of uncertainty results in friction coefficient measurement for scaled brake test rigs, this study employs the GUM and MCM to evaluate the uncertainty of friction coefficients for copper-based powder metallurgy brake pads under a braking pressure of 2.89 kN and braking speeds ranging from 50 to160 km/h. The GUM method calculates uncertainty under the assumption of a normal distribution for input quantities,while the MCM evaluates uncertainty based on the probability distributions of input parameters.Results show that the uncertainty values obtained by the GUM method range from 0.0057 to 0.0061, compared to 0.0045 to 0.0053 for the MCM, with the former being 7% to 25% higher than the latter. This discrepancy arises because the normal distribution assumption in the GUM method is disrupted by the volatility of friction coefficients, which causes data samples to deviate and amplifies uncertainty. In contrast, the MCM reduces the impact of accidental data by incorporating actual probability distributions of input quantities. Conclusively, for friction coefficient measurements in scaled brake test rigs, the uncertainty evaluation results from the MCM method are more appropriate and should be adopted.更多还原