接头中焊缝断裂韧性的概率方法评定

A PROBABILISTIC APPROACH TO EVALUATION OF FRACTURE TOUGHNESS OF WELDS IN WELDED JOINTS

在本研究中依据裂纹张开位移(COD)断裂韧性δ_(cr)和δ_(is),的试验结果,对用LB52NS 焊条施焊的A131钢焊接接头在脆—韧转变温度区间断裂韧性统计性质进行了统计分析研究。并对δ_(cr),值进行了蒙特卡罗法(Monte-Carlo)的模拟处理。结果表明:COD 值δ_(ir),及δ_(cr),的概率密度函数均可由三参数威布尔分布表征。最后依据E(δ_(cr))和D(δ_(cr))的概念,讨论了试验温度及试件尺寸对断裂韧性COD 分布的影响,并给出了有关的数据。

In this investigation the probabilistic natures for fracture toughness of wel-ded joints of A131 steel welded by LB52NS electrode were analysied by means ofstatistic treatment based on the test results of δ_(cr),and δ_(is),in the COD test ofductile/brittle transition temperatures.In addition the probabilistic nature of δ_(cr)was simulated with Monte-Carlo method also.It has been found that the probabi-lity density functions of either δ_(cr),or δ_(is) can be expressed by weibull distribu-tion with three parameters.Finally,the effects of test temperature and size ofspecimen on the distribution of the fracture toughness were discussed based uponthe E(δ_(or))and D(δ_(or))concepts and available date were given.