Welding Defects Fracture Reliability Assessment

The research of assess methods to assure the safety of welding-structure's rupture defect is very popular in our days. This article is a member of them which are based on probability methods to assess defect's safety. The research work mostly fasten on the implement of reliability-assessing's principle and technique in the welding-structure.. The reliability-assessing methods, which are more advanced in this field, are introduced into the assessing and greatly increase its veracity. More, the advantage and formality from reliability-assessing methods make engineering application more convenient and effective.During these decades, the research of applying rupture mechanics to assess defect's safety developed slowly and continuously. Merge of rupture mechanics and Stress-Intensity Factor Solutions touch off research of this field and every important development of rupture mechanics would upgrade assessing technique to a new height(include COD rules and J rules). So, defect assessing technique was closely linked to the development of rupture mechanics.The work in the article include:1. Analysis and compare each important defect assessing criterion or guidance, include ASME IIW PD6493 JWES R/H R6, and bring forward the reliability-assessing methods.2. Experiment on studying the probability assess method of COD3. Based on Invalidation Assessing Chart, bring forward probability methods to assess the 1st kind choice-curve.4. Detailedly analysis the incertitude of all kinds parameter and built their probability distributing model.5. Use Monte-carlo methods and numerical integral methods to calculate the result. Numeration program flow chart is shown.6. Give some engineering example to apply the methods.