基于泰勒展开的航空材料拉伸检测不确定度研究

Research of Uncertainty Based on Taylor's Formula for Tension Testing of Aerial Materials

由实验室设备检测得到的试样的测量值,仅仅是被测量的估计值,测量过程中的随机效应及系统效应,均会导致测量的不准确性,这种不准确性用数值进行衡量,即为该测量值的不确定度。本文使用3D打印合金试验数据,首先通过理论分析,基于泰勒公式研究了尺寸测量引入的不确定度,给出了抗拉强度、屈服强度、断后伸长率和断面收缩率等检测项目测量不确定度的表达式;然后选取同批次航空材料试验数据计算其扩展不确定度;最后通过对试验数据进行分析,研究了基于泰勒展开计算扩展不确定度方法对于预测该种材料的抗拉强度和屈服强度等的扩展不确定度范围的可行性;通过进一步优化该算法,固化流程,设计信息化系统,扩充样本数量并建立数据库进行动态计算,得到优化后的扩展不确定度计算方法,验证了信息化系统对于预测该种材料的断后伸长率和断面收缩率的扩展不确定度范围的可行性。

The measure values of specimens tested by laboratory equipment are only an estimate values for tested object.The random and systemic effect can both produce uncertainty in measurement.Uncertainty in measurement based on Taylor's formula for tension testing of 3D printed aerial alloy is researched in this paper.First,a mathematical calculation method for the uncertainty in measurement based on Taylor's formula is studied,the expressions due to dimension measure of specimens in tensile strength,yield strength,elongation after fracture and reduction of area are given.Secondly,expanded uncertainty of these four testing items which specimens are in the same condition and process are calculated.At last,mathematical calculation method of uncertainty in measurement is given to predict the uncertainty range for such testing items by comparing and analyzing multiple sets of test data;by improving mathematic model,informational system is designed to calculate elongation after fracture and reduction of area through fixed procedure.