TA18钛合金管收缩应变比的测量不确定度评定  

Evaluation of measurement uncertainty of contractile strain ratio of TA18 titanium alloy pipe

作　　者：房永强 余泽利 白新房 张兵 张艺新 王柯 FANG Yong-qiang;YU Ze-li;BAI Xin-fang;ZHANG Bing;ZHANG Yi-xin;WANG Ke(Measurement Center,Xi'an Hantang Analysis and Testing Co.,Ltd.,Xi’an 710003,China)

机构地区：[1]西安汉唐分析检测有限公司计量中心,陕西西安710003

出　　处：《塑性工程学报》2021年第12期230-236,共7页Journal of Plasticity Engineering

基　　金：陕西省创新能力支撑计划项目(2021PT-024)。

摘　　要：对TA18钛合金管的收缩应变比CSR进行了测量,同时建立了周向塑性真应变E_(c)、轴向塑性真应变E_(a)和收缩应变比CSR的数学模型,分析研究了E_(c)和E_(a)的不确定来源,合成了E_(c)和E_(a)的标准不确定度,并对CSR的标准不确定度进行了合成和扩展。结果表明,E;的不确定度主要来源于千分尺示值误差和尺寸测量位置的不一致;E_(a)的不确定度主要来源于放大后的激光刻线边缘阴影部分造成的测量误差;CSR测试结果为:CSR=1.77±0.25,k=2,换算成相对扩展不确定度即U_(rel)=14%,k=2。这表明CSR的相对扩展不确定度较大,当管材CSR测试值达到标准规定极限值的86%时,需充分考虑不确定度。Contractile strain ratio CSR of TA18 titanium alloy pipe was measured, and the mathematical models of true circumferential plastic strain E;, true axial plastic strain E;and contractile strain ratio CSR were established. The uncertainty sources of E;and E;were analyzed and studied, the standard uncertainties of E;and E;were synthesized, and the standard uncertainties of CSR were synthesized and extended. The results show that the uncertainty of E;mainly comes from the indication error of micrometer and the inconsistency of dimension measurement position;the uncertainty of E;mainly comes from the measurement error caused by the shadow part of the edge of the amplified laser scribed line;the CSR test result is: CSR=1.77±0.25,k=2, which is converted into relative expansion uncertainty, that is U_(rel)=14%, k=2. This shows that the relative expansion uncertainty of CSR is large. When the CSR test value of pipe reaches 86% of the limit value specified in the standard, the uncertainty should be fully considered.

关 键 词：TA18钛合金管 收缩应变比 周向塑性真应变 轴向塑性真应变 测量不确定度 

分 类 号：TG146.23[一般工业技术—材料科学与工程]