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本文在分析了按标准试验方法测得的K_(IC)值的分散性产生的原因之后,确认用同种工艺状态、同一取样方向的同种材料制成的同尺寸试样在同一温度下测得的K_(IC)值为随机变量.用大小为43和30的子样分别检验了Lc4与30 CrMnSiNi2A 两种材料上述K_(IC)随机变量的分布特性,认为基本遵循正态分布.利用统计理论估计出取得在90%的置信度下与真值误差小于5%的K_(IC)平均值所需试样数约为4—6.指出在每组K_(IC)试验中用最少试样取得满足上述要求的K_(IC)平均值的具体方法。最后对用三根试样测定的K_(IC)平均值给以统计意义的说明.
After analyzing the reason of dispersion of K_ (IC) value measured by the standard test method, it is confirmed that the same size of sample made of the same material in the same process state and same sampling direction can be measured at the same temperature The K_ (IC) values obtained are random variables.The distribution characteristics of the above K_ (IC) random variables in Lc4 and 30 CrMnSiNi2A materials are tested respectively with the sub samples of sizes 43 and 30, which are considered to follow the normal distribution statistic The theory estimates that the number of samples required to obtain an average value of K IC less than 5% with a true error of less than 5% at a confidence level of 90% is about 4-6, indicating that in each K IC test, Get to meet the above requirements of the K_ (IC) average of the specific methods. Finally, the average value of K_ (IC) measured by three samples is given a statistical description.