钢板断后伸长率测量不确定度的评定

Uncertainty of Measurement Evaluation for Plates Percen tage Elongation after Fracture

为评定钢板断后伸长率的测量不确定度,以轧制厚度为18mm的Q235B板材矩形带头短比例试样为 例,建立了不确定度计算的数学模型,确定了影响试验结果的各项因素:如断后标距Lu、原始标距L0,计算出了各因素的标准不确定度,得出结果的扩展不确定度,并给出最终测量结果的表达式:断后伸长率的最终测量结果为 (28±3)%。

In order to evaluate uncertainty of meas urement of plates percentages elongation after fracture, the maths model to calc ulate uncertainty is established and different factors of influencing testing r esult are fixed on:final gauge length L u and original gauge length L 0,which takes the rectangle head shorter proportional sample of 18 mm Q235B plat es for examlp. Standard uncertainty of different factors is analyzed. Expanded u ncertainty of tensile testing result is figured out and the ultimate result of p ercentages elongation after fracture is(28±3)%.