驱动桥桥壳垂直弯曲刚性试验不确定度计算方法

Uncertainty calculation method for vertical bending rigidity test of driving axle housing

首先根据标准QC/T533-1999试验方法及QC/T534-1999评价指标,试验样件要求重复测量三次8种负荷工况下,驱动桥桥壳的变形量,以满载轴荷时的每米轮距的最大变形量作为合格与否的评价指标。在确定数学模型后,其不确定度来源初步估计有测量的重复性引入的不确定度、百分表的标准不确定度、设备载荷传感器的不确定度间接引起的位移不确定度。通过分项计算再合成后,从结果可以得出,经过标定校准的设备及测量仪器引入的不确定度几乎可以忽略,不确定度的大部分因素主要还是由人员重复测量引入。

Firstly, according to the standard QC/T 533-1999 test method and QC/T 534-1999 evaluation index, the deformation of the bridge shell under 8 load conditions is required to be measured repeatedly for three times for the test sample, and the maximum deformation per meter of wheelbase under full load is taken as the evaluation index of whether it is qualified or not. After the mathematical model is determined, the sources of the uncertainty are initially estimated as the uncertainty introduced by the repeatability of measurement, the standard uncertainty of the dial indicator, and the displacement uncertainty indirectly caused by the uncertainty of the load sensor of the equipment. The results show that the uncertainty introduced by calibrated equipment and measuring instruments can be almost ignored, and most of the uncertainty factors are mainly introduced by repeated measurement.