Statistic distribution of resistance to initiation property of high density polyethylene gas pipe butt-fusion welded joint

The statistic distribution of the resistance to initiation property of HDPE(high density polyethylene) pipe butt-fusion welded joint was investigated on the basis of Crack Opening Displacement(COD).The results show that the saturation initial crack COD δ_is of HDPE butt-fusion welded joint have the statistic variance inherently.The statistic probabilistic model was set up to fit the distribution function of δ_is.Performed several statistic tests,the results show that the optimum fitting distribution of δ_is weibull distribution with three parameters.The variance of test results decreases with decreasing temperature.