大型焊接结构疲劳寿命评估研究综述

REVIEW OF RESEARCH ON FATIGUE LIFE EVALUATION FOR LARGE WELDED STRUCTURES

大型焊接结构在各重大装备领域有着广泛的应用,其寿命评估对于设备安全服役至关重要。对大型焊接结构疲劳寿命评估方法进行了综述,对名义应力法、缺口应力法、热点应力法、等效结构应力法的原理、思路、优缺点及各自适用范围进行了比较、分析和总结,结果表明:名义应力法简单方便,可用于各领域的简单焊接结构分析;热点应力法在海洋船舶领域应用最为广泛;缺口应力法建模及求解过程复杂,对焊趾和焊根的疲劳分析均适用;等效结构应力法具有网格不敏感性,可以通过一条主S-N曲线将各种焊接接头的应用统一起来,具有良好的工程应用潜力。在此基础上,分门别类地介绍了轨道交通、船舶、桥梁、工程机械、车辆等领域大型焊接结构疲劳寿命评估的现状;分析了大型焊接结构疲劳寿命预测的主要难点和问题,为今后大型焊接结构的疲劳寿命评估方法的发展提供参考和思路。

Large welding structures have been widely used in various major equipment fields. Life evaluation of welding structures is very important for equipment safety.The fatigue life assessment methods including nominal stress method, notch stress method, hot spot stress method and equivalent structural stress method are summarized for large welded structures. The basic principles, advantages and disadvantages of various methods are compared and analyzed. The results show that the nominal stress method is simple and convenient, and can be used for simple welding structure analysis in various fields;the hot spot stress method is widely used in the field of marine ships;the notch stress method is complex in modeling and solving, and it can be used for both fatigue analysis of butt weld toe and weld root;the equivalent structural stress method is mesh insensitive, and can unify the application of various welded joints by a main SN curve, and has great potential application for engineering. The fatigue life assessment of large welded structures application in the fields of rail transit, ships, bridges, construction machinery and vehicles are introduced. The main difficulties and problems in the fatigue life prediction of the large welded structures at the emerging stage are analyzed. It provides references and ideas for the development of fatigue life evaluation methods for the large welded structures in the future.