用局部法评定焊接接头的疲劳性能  

Estimation of fatigue performance of welded joints by local approaches

作　　者：吴冰[1] 杨新岐[1] 贾法勇[1] 霍立兴[1] 

机构地区：[1]天津大学材料科学与工程学院,天津300072

出　　处：《焊接学报》2003年第6期51-54,共4页Transactions of The China Welding Institution

基　　金：国家博士基金资助项目(19999005605)

摘　　要：采用16Mn钢非承载十字焊接接头疲劳试验结果对使用DangVan准则的疲劳评定局部方法进行了研究。结果表明,有限元分析中应力集中区单元尺寸对局部参量计算有明显影响,为获得比较合理的预测结果需对焊趾应力集中区所划分的单元尺寸限定,当接头焊趾半径在0.15～0.8mm变化时应选择最小单元尺寸0.32～0.62mm计算局部参量;在此基础上DangVan准则可以对焊态接头做出合理的评定,但DangVan建议的β值偏安全。此外,通过计算发现焊趾半径只影响局部很小区域(约0.5mm内)的应力集中分布,在某一深度(约0.5mm)后存在稳定的应力集中,因而建议采用距应力集中区最大应力处某一深度的应力参数计算DangVan局部参量可能更为合理,这将减小局部参数对焊趾半径及单元尺寸的依赖性。The fatigue assessment using the Dang Van criterion by local approaches was studied according to the results of fatigue tests of 16Mn non-carrying-load cruciform welded joints. It is shown that the minimum element size of EFA in the stress concentration zone has apparent effects on the calculation of the local parameters. When the radius of the weld toes ranges from 0.15 to 0.8 mm, the reasonable predicting results can be obtained if the local parameters are calculated by selecting the minimal element size in the range of 0.32-0.62 mm, and the local approaches using the Dang Van criterion can reasonably assess the fatigue behavior of welded joints, but the value of β is conservative. Additional, we find that the radius of weld toes mainly affect the local distributions of stress concentration in the small region (r<0.5 mm), and there is the stable stress concentration when the depth is above the value (r≥0.5 mm). Thus it will be more reasonable if the local stress parameters at the point away from the site of the maximal stress are used to calculate the Dang Van local parameters. This could reduce the dependence of Dang Van local parameters on the geometries of welded toe and local element sizes.

关 键 词：焊接接头 疲劳性能 局部法 评定 有限元 应力集中 单元尺寸 

分 类 号：TG405[金属学及工艺—焊接]