关键词：钢铁；随机分布；断裂韧性；X65钢压力管；计算机分析
摘 要：It is important for the design engineer to realize that scatter and variability of materials properties are inevitable and must be dealt with appropriately.The program,which plays an important role in structure reliability analysis,can be used to determine the probability statistic distribution of the mechanical properties.The calculated results indicate that the weld fracture toughness of the X65 pressure pipe steel can either accord with normal distribution,lognormal distribution or weibull distribution,but the optimum fitting distribution of the fracture toughness cδc is weibull distribution.