摘要
采用三维弹塑性有限元技术,对内压载荷作用下含纵向穿透裂纹弯头的塑性极限载荷进行了系统分析。结果表明,裂纹削弱系数(PL/PL0)与厚径比(t/rm)无关,在实际工程应用中可忽略厚径比对裂纹削弱系数的影响。裂纹对长半径弯头的塑性极限承载能力影响程度明显大于对短半径弯头的。
Elbow is a type of component widely used in a piping system. So it is very important to know the effects of cracks on the collapse loads of elbows for integrity assessment of the piping system. The influences of defects on the load carrying capacity of elbows with various bending radius （ R/= 1.0 Di and R/= 1.5 Di ）, were investigated in detail, by three- dimensional （3D） non- linear finite element （FE） analyses, using elastic- perfectly - plastic material behavior and taking geometric nonlinearity into account. The crack - like defects with different dimensions were focused on axial through - wall cracks, located in extrados, intrados and crown of elbow with the welded tangent straight pipes respectively. The results from comprehensive parametric studies on limit loads of elbows indicate that the limit load capacity of cracked elbows may be reduced with the increasing of crack length and these trends are more serious for long radius elbows. These is insignificant effects of t/rm on the weakening factor （ PL/PL0 ） of cracked elbows subjected to internal pressure. This paper is useful for safety assessment of the cracked elbows.
出处
《压力容器》
北大核心
2005年第8期6-9,共4页
Pressure Vessel Technology
基金
国家"十五"重大科技攻关资助项目(2001BA803B03-05)。
关键词
弯头
塑性极限载荷
穿透裂纹
内压
非线性有限元分析
elbows
limit loads
through - wall cracks
intemal pressure
non - linear finite element （FE） analyses
