X100管线钢裂纹体的弹塑性断裂失效分析  

Constraint effect and fracture behaviour for X100 pipeline steel

作　　者：王钟羡[1] 黄建业[1] 

机构地区：[1]江苏大学理学院,江苏镇江212013

出　　处：《江苏大学学报（自然科学版）》2011年第2期175-178,231,共5页Journal of Jiangsu University：Natural Science Edition

基　　金：国家"863"计划项目(2008AA100905)

摘　　要：运用弹塑性断裂理论并结合有限元数值分析,定量研究了带轴向裂纹管线钢X100的断裂行为.在J-Q双参数理论的基础上,考虑塑性效应的影响,引入一个新参数βQ,建立了J-βQ双参数断裂准则.结合JR-Δa试验结果,得到X100钢的断裂失效曲线,并对带轴向内、外裂纹管道的临界压力值进行预测.计算结果表明,外表面裂纹的约束比内表面裂纹高,但当裂纹a/δ≤0.18时则情况相反;在裂纹尺寸比较小时(a/δ≤0.40),裂纹尖端场所受约束较弱,塑性变形比较大,管道以屈服破坏为主,用PCORRC方法确定临界压力是偏于安全的;在裂纹尺寸比较大时,约束加强,塑性变形比较小,管道以断裂破坏为主.Constraint effect and fracture behaviour for X100 pipeline steel with axial crack were quantitatively studied by elastic-plastic fracture theory combined with FEA.Considering the plastic effects,a parameter βQ was introduced on the basis of J-Q theory and the fracture criterion of J-βQ double parameters was established.The failure curve of X100 was fitted from the data of JR-Δa experiment.Failure pressures for pipelines with internal and external axial cracks were predicted separately.The results show that constraint effect of the external crack is little stronger than the internal crack,but it is opposited when a/δ≤0.18.For shallow cracks（a/δ≤0.40）,crack tip fields are not very constrained and yield failure is most likely to occur as plastic deformation is larger,the failure pressure of pipeline corrosion criterion（PCORRC） is conservative.For deep cracks,strengthened constraint effect results in small plastic deformation and fracture failure will take place.

关 键 词：X100管线钢 裂纹 断裂 约束 有限元分析 

分 类 号：TB12[理学—工程力学] TK222[理学—力学]