焊接接头缺陷尺寸概率分布模型研究

摘要

Statistical distribution research on welding defect size in weld joints was investigated based on engineering physics background of welding defect occurring and mathematics statistics. The research showed that the frequency of defects occurring obeyed Poisson process and that the ratio of defect occurring was invariable in a certain weld metal area. The study on the frequency of defects occurring and the ratio of defect occurring showed that welding defect size obeyed index distribution. By means of parameters estimation and mathematics statistics on ADB610 steel penstock in water conservancy and hydropower engineering, it was found that index distribution was the best one for welding defects size. It can be concluded that welding defect size obeys index distribution from both study on engineering physics background and study by means of mathematics statistics method. So it is put forward that index distribution is the real statistical distribution for welding defect size in weld joints.%从焊接缺陷的工程物理意义和数理统计的角度,对焊接接头缺陷的尺寸进行概率分布模型的研究.提出焊接缺陷在一段焊缝长度区间上产生的缺陷数符合泊松分布过程,以及缺陷产生的比率相等、为常数,并从这两个物理背景进行研究,推导出焊接接头缺陷尺寸的分布应该属于指数分布.对水利水电工程中ADB610钢引水压力管道焊接接头采用X射线检测到的实际焊接缺陷尺寸数据运用最小二乘法和线性相关系数检验法进行数理统计研究,认为焊接缺陷尺寸更好地服从指数分布.从物理意义和数理统计两方面,都表明焊接缺陷尺寸服从指数分布,两方面研究的结论相统一,因此,提出指数分布是焊接接头缺陷尺寸的真实统计分布模型,为后续进行焊接结构的可靠性评定、寿命预测奠定基础.