面内开/闭弯载荷作用下压力管道弯头的塑性载荷研究

Plastic Collapse Loads for Piping Elbows under In-plane Open/Close Bending Moment

采用弹塑性有限元分析技术,将材料简化为理想弹塑性,同时考虑几何非线性影响,针对不同厚径比t/rm、相对弯曲半径R/rm和弯曲模式下有直管连接弯头的弹塑性行为进行了系统分析,在此基础上分别建立了便于工程应用的无缺陷弯头在开、闭弯作用下的塑性载荷估算式。试验研究表明本文建立的面内开/闭弯塑性载荷估算式能够满足工程实际需要。

Elbow is a type of component widely used in a piping system. So it is very important to know the plastic load carrying capacity of elbow. The experiments and non - linear finite element （FE） analyses indicated that under the open/close bending modes, elbow exhibited different behavior obviously, at the elastic - plastic states. By three- dimensional （3D） non- linear finite element （FE） analyses, using elastic - perfectly- plastic material behavior and taking geometric nonlinearity into account, the elastic - plastic behavior of elbows with various ratios of t/rm and relative bending radius R/rm were investigated in detail, and the closed form equations were established. The comparison of predictions from these newly proposed collapse load equations with experimental data validated that these equations can be used to evaluate the collapse moment for defect - free elbow in engineering practice.