塑性应变比测量的研究

The research of measurement of plastic strain ratio

分析了测试r值的国家标准GB／T5027—2007和GB／T5027—1999的区别，利用大量试验证明了不同应变水平下，采用“真实应变”和“真实塑性应变”对r值结果没有显著影响；同时研究了拉伸速率对r值的影响和两种不同的手工测量r值方法之间的差异，并对r值测量不确定度进行了讨论。

Analyzed the difference between the state standards GB/T 5027-2007 and GB/T 5027-1999 for testing r value, demonstrated there will be no obvious influence on r value by adopting either ＂authentic strain＂ or ＂authentic plastic strain＂ under different strain levels via large amount of experiments; meanwhile, researched the impact on r value brought by tensile rate ＆ the disparity between two different manual ways for measuring r value, also launched discussion on the uncertainty of r value measurement.