关于金属材料室温拉伸试验标准GB/T 228.1-2010的探讨
Discussion on Tensile Test Standard GB/T 228.1-2010 of Metallic Materials at Room Temperature
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摘要: 从应力控制和应变控制方面着手,分析了金属材料拉伸试验标准GB/T 228.1-2010中方法 A和方法B的速率控制问题。从实际应用方面比较了方法 A和方法 B的优劣并讨论了其应用难点,对弹性段的拉伸速率是否影响试验结果进行了分析。结果表明:应力速率和应变速率均为平均速率或设定的速率,拉伸过程中实时的速率会随着空间和时间变化而不断变化;标准中规定的应力速率范围或等效应变速率范围内,弹性段拉伸速率对测量结果影响很小。指出夹具的间隙问题目前还不能完全解决,即刚度修正的前提不存在。对该标准的修订提出了建议。Abstract: Starting from the aspects of stress control and strain control,the rate control of method A and method B in the standard GB/T 228.1-2010 for tensile test of metal materials was analyzed.The advantages and disadvantages of method A and method B were compared from practical application and the difficulties in application were discussed.The influence of the tensile rate of elastic segment on the test results was analyzed.The results show that both stress rate and strain rate were average rates or the set rate.The real-time rate in the stretching process would change with space and time.In the range of stress rate or equivalent strain rate specified in the standard,the tensile rate of elastic segment has little influence on the measurement results.It is pointed out that the gap problem of fixture can not be completely solved up to now,since the premise of stiffness correction does not exist at present.Suggestions are made for the revision of the standard.