Plastic loads for 90° thick-walled elbows under combined pressure and bending

Kim, Y. J.; Je, Jin Ho; Oh, Chang Sik; Han, Jung Suk; Budden, P. J.

doi:10.1243/03093247jsa568

Cited by 24 publications

(4 citation statements)

References 22 publications

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“…A total of 1800 models were solved for different bend angles and the corresponding reaction moment was extracted for each model where the rotation boundary condition was given. The TES or HES method 40 was utilised to get the collapse load for each model of rotation moment curve (RMC). In this method, the slope of the initial elastic region was doubled to draw the line from its origin to meet the RMC to obtain the collapse load.…”

Section: Details Of the Current Fe Analysis Proceduresmentioning

confidence: 99%

Determination of bend angle and shape imperfection effect on collapse load of pipe bends under in-plane opening moment

Silambarasan

Veerappan

Shanmugam

2022

Proceedings of the Institution of Mechanical Engineers, Part E:

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This study uses a three-dimensional nonlinear finite-element method to investigate the effects of bend angle ([Formula: see text]) and shape imperfection on the collapse load of pipe bends subjected to in-plane opening bending moment using large displacement analysis. ABAQUS was used to create a pipe bend model, whereas by virtue of symmetry about the longitudinal axis, half of the pipe bend model was built. The bend angle was varied from 30° to 180° with an interval of 30°, and shape imperfections, namely ovality ( Co) and thinning ( Ct), were varied from 0% to 20% each at 5% intervals. Elastic-perfectly plastic is thought to be the material of choice for the pipe bend. The results show that the bend angle has a significant impact on the collapse load of pipe bends between 30° and 120°, after which a significant decline was observed. The ovality impact increases with an increase in bend angle for pipe bends with a large thickness, whereas the opposite effect was found for smaller thicknesses with a small bend radius. The effect of bend radius and thickness was significant for large bend angles. Thinning ( Ct) and thickening ( Cth) have no effect on collapse load. A new mathematical equation has been proposed to predict the integrated effect of bend angle and shape imperfection.

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Section: Details Of the Current Fe Analysis Proceduresmentioning

confidence: 99%

Determination of bend angle and shape imperfection effect on collapse load of pipe bends under in-plane opening moment

Silambarasan

Veerappan

Shanmugam

2022

Proceedings of the Institution of Mechanical Engineers, Part E:

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“…20,21 To include the large geometry change in the analysis, Nlgeom is toggled on while creating the Static Riks step. 22…”

Section: Loading and Boundary Conditionsmentioning

confidence: 99%

Determination of collapse moment of different angled pipe bends with initial geometric imperfection subjected to in-plane bending moments

Kumar

Roy

Khan

2021

Proceedings of the Institution of Mechanical Engineers, Part C:

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From the recent literature, it is revealed that pipe bend geometry deviates from the circular cross-section due to pipe bending process for any bend angle, and this deviation in the cross-section is defined as the initial geometric imperfection. This paper focuses on the determination of collapse moment of different angled pipe bends incorporated with initial geometric imperfection subjected to in-plane closing and opening bending moments. The three-dimensional finite element analysis is accounted for geometric as well as material nonlinearities. Python scripting is implemented for modeling the pipe bends with initial geometry imperfection. The twice-elastic-slope method is adopted to determine the collapse moments. From the results, it is observed that initial imperfection has significant impact on the collapse moment of pipe bends. It can be concluded that the effect of initial imperfection decreases with the decrease in bend angle from 150∘ to 45∘. Based on the finite element results, a simple collapse moment equation is proposed to predict the collapse moment for more accurate cross-section of the different angled pipe bends.

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“…A python script was used to create the input file for each pipe bend model and perform the analysis in ABAQUS software. The moment rotation curve was plotted for all simulated pipe bend models from which plastic collapse load was determined by using the twice elastic slope (TES) method (Kim et al , 2010). A typical moment rotation curve with TES point is shown in Figure 4.…”

Section: Finite Element Analysismentioning

confidence: 99%

Effect of structural deformations and bend angle on the collapse load of pipe bends subjected to in-plane closing bending moment

Silambarasan

Veerappan

Shanmugam

2021

WJE

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Purpose The purpose of this study is to investigate the effect of structural deformations and bend angle on plastic collapse load of pipe bends under an in-plane closing bending moment (IPCM). A large strain formulation of three-dimensional non-linear finite element analysis was performed using an elastic perfectly plastic material. A unified mathematical solution was proposed to estimate the collapse load of pipe bends subjected to IPCM for the considered range of bend characteristics. Design/methodology/approach ABAQUS was used to create one half of the pipe bend model due to its symmetry on the longitudinal axis. Structural deformations, i.e. ovality (Co) and thinning (Ct) varied from 0% to 20% in 5% steps while the bend angle (ø) varied from 30° to 180° in steps of 30°. Findings The plastic collapse load decreases as the bend angle increase for all pipe bend models. A remarkable effect on the collapse load was observed for bend angles between 30° and 120° beyond which a decline was noticed. Ovality had a significant effect on the collapse load with this effect decreasing as the bend angle increased. The combined effect of thinning and bend angle was minimal for the considered models and the maximum per cent variation in collapse load was 5.76% for small bend angles and bend radius pipe bends and less than 2% for other cases. Originality/value The effect of structural deformations and bend angle on collapse load of pipe bends exposed to IPCM has been not studied in the existing literature.

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Plastic loads for 90° thick-walled elbows under combined pressure and bending

Cited by 24 publications

References 22 publications

Determination of bend angle and shape imperfection effect on collapse load of pipe bends under in-plane opening moment

Determination of bend angle and shape imperfection effect on collapse load of pipe bends under in-plane opening moment

Determination of collapse moment of different angled pipe bends with initial geometric imperfection subjected to in-plane bending moments

Effect of structural deformations and bend angle on the collapse load of pipe bends subjected to in-plane closing bending moment

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