New formula for predicting the plastic buckling pressure of steel torispherical heads under internal pressure  

作　　者：Sheng YE Keming LI Jinyang ZHENG Shan SUN 

机构地区：[1]Institute of Process Equipment,Zhejiang University,Hangzhou 310027,China [2]Engineering Research Center for High Pressure Process Equipment and Safety of Ministry of Education,Hangzhou 310027,China [3]State Key Laboratory of Fluid Power and Mechatronic Systems,Hangzhou 310058,China

出　　处：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》2024年第8期618-630,共13页浙江大学学报（英文版）A辑（应用物理与工程）

基　　金：supported by the National Natural Science Foundation of China(No.52105161).

摘　　要：Thin-walled torispherical heads under internal pressure can fail by plastic buckling because of compressive circumferential stresses in the head knuckle.However,existing formulas still have limitations,such as complicated expressions and low accuracy,in determining buckling pressure.In this paper,we propose a new formula for calculating the buckling pressure of torispherical heads based on elastic-plastic analysis and experimental results.First,a finite element(FE)method based on the arc-length method is established to calculate the plastic buckling pressure of torispherical heads,considering the effects of material strain hardening and geometrical nonlinearity.The buckling pressure results calculated by the FE method in this paper have good consistency with those of BOSOR5,which is a program for calculating the elastic-plastic bifurcation buckling pressure based on the finite difference energy method.Second,the effects of geometric parameters,material parameters,and restraint form of head edge on buckling pressure are investigated.Third,a new formula for calculating plastic buckling pressure is developed by fitting the curve of FE results and introducing a reduction factor determined from experimental data.Finally,based on the experimental results,we compare the predictions of the new formula with those of existing formulas.It is shown that the new formula has a higher accuracy than the existing ones.

关 键 词：Torispherical head Plastic buckling Elastic-plastic analysis Prediction formula Finite element method 

分 类 号：O34[理学—固体力学] TP39[理学—力学]