The Reliability Design And Analysis Technology Of Welding Technology Based On The Defects

With the rapid development of welding technology, welding process has evolved into one of the advanced manufacturing technology from a traditional processing technology and material connection methods, it is playing an increasing important role in national economic development, it is also developing toward large-scale, precision and high parameters constantly. So it has more strict requirements on the manufacturing quality of welded structure, welding technology is the core of the welding technology, not only determine the welding quality of products, but also affect the efficiency and economy of welding production directly. Welding process reliability problems become more and more prominent.This paper researches on mechanism of typical welding defects based on typical failure modes (brittle fracture?fatigue destruction?stress corrosion cracking) of the welding structure, and then finds the factors of welding process reliability:all kinds of weld defects (especially the welding crack) are failure source and the main failure reason of the welding structure, then has a mechanism analysis on the typical welding defect and finds the influence factors of welding process reliability, including four aspects:the factor of welding process, the factor of welding material, the factor of welding joint and the factor of welding environment, then has a organizing analysis on the reliability influence factors, and finds the properties of each reliability factor. Having a screening on the influence factors of reliability of welding process by using three-step screening method:the screening of technical?the screening of control?the screening of orthogonal test design based on the specified task of welding, finds the main quantitative factors of welding process reliability(four or less)?then uses experimental design method of uniform experimental design to build the relationship between mechanics performance parameters of the welding process reliability and the main quantitative factors based on the second order response surface model and specified mechanical performance parameters of welding process reliability. Then with the help of Matlab software, find the display of the relation between the obtained model by using the least square method, then control the accuracy of model by using residual analysis (standard residual error estimator? standard residuals chart), basing on the mechanical performance parameters allowable value of the welding process reliability and the form of distribution of main factors affecting reliability, with the help of Matlab software, finds the calculation method of defects probability for welding process reliability model by using the monte carlo method, then finds the key influence factor (only one) of welding process reliability model by using sensitivity analysis method.The paper help reduce welding structure defects of welding process, optimize welding process, reduce the failure probability of welding structure, improve the reliability of welding process, provide a complete set of reliability analysis method for welding process, and has an important significance on national economic development and national defense development of our country.