摘要
采用有限元方法,建立了斜接管压力容器结构在内压作用下的数值模型,并将不同载荷下管道的热点应力分布与现有文献实验结果进行了比较,两者吻合较好,验证了该计算方法的可靠性。对于正交接管利用两倍弹性斜率、切线交点和零曲率极限载荷准则获得斜接管道失效的极限内压;并将正交接管的极限内压与Cloud以最大有效应力达到屈服时对应的理论上极限内压值进行比较,结果表明:两倍弹性斜率与切线交点极限载荷准则在预测极限内压时偏于保守,零曲率准则对确定斜接管压力容器的极限载荷比较恰当。然后利用零曲率准则确定斜接管压力容器的极限载荷,采用控制单变量变化的方法,分别分析了接管中心线与筒体中心的夹角、接管与筒体直径之比和筒体厚度与直径之比对极限载荷的影响,最后综合考虑这些因素的影响,得出了斜接管压力容器极限载荷的近似计算式。提供的分析方法为压力容器的设计及安全性评定提供了一种新途径。
By use of finite element method, the numerical model of slant nozzle subjected to internal pres- sure was set up and the hot stress distribution of the nozzle under different loading was compared with the existing experimental results, showing that they were in good agreement. The critical values of internal pressure in orthogonal nozzle were obtained by three critical load criterions of double slope of elastic curve, point of tangent line and zero curvature and they were compared with the theoretical values pro- posed by Cloud using maximum effective stress when yielding. The results showed that it is conservative for the criterions of double slope of elastic curve and point of tangent line to predict the critical loads and it is appropriate for the zero curvature criterions to determine the critical load. With the single - variable approach, the effects of the angle of center lines in the connected tube and vessel, the ratio of diameters between them and the ratio of thickness and diameter of the vessel were analyzed respectively. Finally, an approximate formula for critical load of slant nozzle was obtained as all factors were consid- ered. The proposed analysis method in this paper could be valuable as a reference for design and security evaluation of pressure vessels.
出处
《压力容器》
北大核心
2010年第8期6-12,共7页
Pressure Vessel Technology
基金
西气东输管道工程项目(07H461)
四川大学"985--西南资源环境与灾害防治科技创新平台"引进人才项目
关键词
斜接管
压力容器
极限载荷
有限元
slant nozzle
pressure vessel
critical load
finite element
