Nonlinear Buckling Analysis of Steel Cylindrical Shell with Elliptical Cut-out Subjected to Longitudinal Compressive Load

The current paper investigates the effect of cut-out design parameters on load-bearing capacity and buckling behaviour of steel cylindrical shell using a nonlinear finite element analysis in modelling cylinder buckling under longitudinal compressive load. The effect of four geometry design parameters: shell diameter to thickness ratio, cut-out location, orientation, and size were investigated in this study. To enhance the prediction of buckling behaviour, both geometrical and material nonlinearities were considered. An ANSYS APDL code was written and tested by verifying its validity through comparison with former buckling study. The results showed that changing the cut-out location from mid-height of the cylindrical shell towards a fixed edge caused an increase in the buckling load value. Moreover, the study showed that increasing parameters such as shell thickness and cut-out orientation have a positive influence in which the buckling load value increased too. For fast design purposes, an empirical numerical based regression formula was presented for the calculation of the critical buckling load of a cylindrical shell having an elliptical cut-out.

Indentation of the cylindrical shell in the elastoplastic half-space

The article deals with the problem of pressing the steel cylindrical shell into the elastoplastic half-space having a cylindrical concavity. The calculation and analysis of the stress-strain state of the steel shell and elastoplastic half-space. Given the dependence of the shear half-space, the safety factor and stress state in steel shell from the force pushing the shell in the half-space. The calculations were carried out for three radii of concavities and two types of half-space materials. It was assumed that the elastoplastic half-space obeys the Mohr-Coulomb fracture criterion.

Influence of Cutout Position on Buckling of Large-Scale Thin-Walled Cylindrical Shell of Desulphurizing Tower with Welding Induced Imperfection under Wind Loading

Not only the geometrical imperfection induced by welding but also cutouts will influence the buckling of large-scale thin-walled steel cylindrical shell under wind loading. Based on the practical cylindrical shells of a desulphurizing absorption tower, in consideration of the correlation between welding induced imperfection and circular cutouts, the influence of cutout position on buckling of cylinder under wind loading is investigated by nonlinear finite element method. The results indicate that the buckling capacity varies slightly when the cutout position moves along meridional direction in the neighboring region of welding imperfection. The buckling capacity varies significantly when the cutout position moves circumferentially as the cutout is located in the welding imperfection. The buckling capacity reaches the minimum value as the cutout is located in the buckle center of cylindrical shells without cutout.

Dynamic Buckling Behaviors of Steel Cylindrical Shell Subjected to Conventional Explosion Impact Loading

Experimental and numerical simulation researches were presented on dynamic buckling behaviors of cylindrical shell subjected to explosion loading.An account is given of some principal observations made from a series of experiments in which steel cylindrical shells were subjected to central impact by 200g cylindrical TNT dynamite with different distances.By means of an finite element computer code LS-DYNA,the nonlinear dynamic response process of the cylindrical shells subjected to explosion loading were numerically simulated with Lagrangian-Eulerian coupling method. The numerical simulation results were in good agreement with experimental data. The results provide a reference for the design of explosion-resisting structures.

Research on Dynamic Response of Q235 Steel Cylindrical Shell Subjected to Lateral Explosion Loading

Experimental researches were presented on dynamic characteristics of Q235 steel cylindrical shell impacted-explosive laterally by 75g cylindrical TNT dynamite at the center．The dynamic response was obtained under different distances with different setting ways of explosive sources．By means of an explicit nonlinear dynamic finite element computer code LS-DYNA，the nonlinear dynamic response process of cylindrical shell subjected to laterally explosion loading were numerically simulated with ALE coupling method. The numerical simulation results were in good agreement with experimental data. The results provided important reference for the blast-resistant properties analysis and safety assessment of oil-gas pipes safety.