Mobilization of Fully Plastic Moment Capacity for Pressurized Pipes

1999 ◽  
Vol 121 (4) ◽  
pp. 237-241 ◽  
Author(s):  
M. Mohareb ◽  
D. W. Murray
Keyword(s):  
Internal Pressure ◽  
Axial Force ◽  
Yield Criterion ◽  
Axial Loading ◽  
Experimental Results ◽  
Moment Capacity ◽  
Interaction Diagram ◽  
Von Mises ◽  
Force Pressure ◽  
Good Agreement

An analytical expression is derived for the prediction of fully plastic moment capacity of pipes subjected to axial loading and internal pressure. The expression is based on the von Mises yield criterion. The expression predicts pipe moment capacities that are in good agreement with full-scale experimental results. A universal nondimensional moment versus effective axial force-pressure interaction diagram is developed for the design of elevated pipe lines.

Tube-Bulging Under Internal Pressure and Axial Force

1973 ◽  
Vol 95 (4) ◽  
pp. 219-223 ◽  
Author(s):  
D. M. Woo
Keyword(s):  
Internal Pressure ◽  
Numerical Solution ◽  
Axial Force ◽  
Compressive Load ◽  
Experimental Results ◽  
Longitudinal Stress ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Tube Bulging

A numerical solution for analysis of the bulging process of a thin-walled tube under internal pressure and axial force is proposed. The solution is applied to a case in which the longitudinal stress resulted from internal pressure and external compressive load is tensile along the whole length of the bulged tube. To verify whether the solution is applicable, theoretical and experimental results on the bulging of copper tubes have been obtained and are compared in this paper.

Fatigue Fracture Behavior of Steel Pipes With a Pre-Crack

2002 ◽  
Author(s):  
Jae-Kyoo Lim ◽  
Lichun Bian
Keyword(s):  
Fatigue Crack ◽  
Yield Criterion ◽  
Axial Loading ◽  
Potential Drop ◽  
Maximum Tensile Stress ◽  
Core Region ◽  
Fracture Criteria ◽  
Steel Pipes ◽  
Inclined Angle ◽  
Von Mises

The behaviour of fatigue crack propagation of mild steel pipes, each consisting of an inclined semi-elliptical crack, subjected to axial loading was investigated both experimentally and theoretically. The inclined angle of the crack with respect to the axis of loading varied between 0° and 90°. In the present investigation, the gowth of the fatigue crack was monitored using the AC potential drop technique. The Von Mises yield criterion was applied to define the core region, instead of assuming a core region with a constant distance r from the crack lip. The two commonly employed fracture criteria, i.e., the maximum tensile stress and the minimum strain energy density criteria, were modified by adopting Von Mises elasto-plastic boundary. The results obtained using the innproved fracture criteria are, in most cases, in better agreement with test results as compared with those obtained using the commonly employed fracture criteria.

Design Equation for Minimum Required Thickness of a Cylindrical Shell Subject to Internal Pressure Based on Von Mises Criterion

2019 ◽  
Author(s):  
James Lu ◽  
Barry Millet ◽  
Kenneth Kirkpatrick ◽  
Bryan Mosher
Keyword(s):  
Cylindrical Shell ◽  
Internal Pressure ◽  
Yield Criterion ◽  
Design Equation ◽  
Shell Wall ◽  
Section Viii ◽  
Von Mises Yield Criterion ◽  
Von Mises ◽  
Division 2 ◽  
Shell Wall Thickness

Abstract Design equation (4.3.1) for the minimum required thickness of a cylindrical shell subjected to internal pressure in Part 4 “design by rule (DBR)” of the ASME Boiler and Pressure Vessel Code, Section VIII, Division 2 [1] is based on the Tresca Yield Criterion, while design by analysis (DBA) in Part 5 of the Division 2 Code is based on the von Mises Yield Criterion. According to ASME PTB-1 “ASME Section VIII – Division 2 Criteria and Commentary”, the difference in results is about 15% due to use of the two different criteria. Although the von Mises Yield Criterion will result in a shell wall thickness less than that from Tresca Yield Criterion, Part 4 (DBR) of ASME Division 2 adopts the latter for a more convenient design equation. To use the von Mises Criterion in lieu of Tresca to reduce shell wall thickness, one has to follow DBA rules in Part 5 of Division 2, which typically requires detailed numeric analysis performed by experienced stress analysts. This paper proposes a simple design equation for the minimum required thickness of a cylindrical shell subjected to internal pressure based on the von Mises Yield Criterion. The equation is suitable for both thin and thick cylindrical shells. Calculation results from the equation are validated by results from limit load analyses in accordance with Part 5 of ASME Division 2 Code.

Mixed Mode Fatigue Fracture Criteria for the Plates With an Inclined Semi-Elliptical Crack

2000 ◽  
Author(s):  
Lichun Bian ◽  
Ai Kah Soh
Keyword(s):  
Fatigue Crack ◽  
Mixed Mode ◽  
Yield Criterion ◽  
Axial Loading ◽  
Maximum Tensile Stress ◽  
Core Region ◽  
Elliptical Crack ◽  
Mixed Mode Fracture ◽  
Fracture Criteria ◽  
Von Mises

Abstract The behaviour of fatigue crack propagation of rectangular steel plates, each consisting of an inclined semi-elliptical crack, subjected to axial loading was investigated both experimentally and theoretically. The inclined angle of the crack with respect to the axis of loading varied between 0° and 90°. In the present investigation, the Von Mises yield criterion was applied to define the core region, instead of a core region with a constant distance r from the crack tip. Based on Von Mises elasto-plastic boundary, the two commonly used fracture criteria, the maximum tensile stress and the minimum strain energy density criteria, were modified. The results obtained using the two improved fracture criteria were compared with those obtained using the commonly used mixed mode fracture criteria and experimental results. A mixed mode fatigue crack criterion has been established based on the experimental data.

The Role of Friction in Metal Cutting

1960 ◽  
Vol 82 (4) ◽  
pp. 324-332 ◽  
Author(s):  
S. Kobayashi ◽  
E. G. Thomsen
Keyword(s):  
Metal Cutting ◽  
Yield Criterion ◽  
Manganese Sulfide ◽  
Experimental Results ◽  
Friction Mechanism ◽  
Contact Areas ◽  
General Rules ◽  
The Difference ◽  
Von Mises

Metal-cutting studies were made with free-cutting steel SAE 1112 and alloy steel SAE 4135 in the as-received condition with artificially controlled tool-chip contact areas and flank contact areas (artificial wear lands). The experimental results for steel SAE 1112 at a speed range of 0.083 to 1010 fpm, reveal that friction under metal-cutting conditions on the rake face can be explained satisfactorily by a junction model with possible superimposed general plastic flow above the junctions in accordance with the general rules of plastic deformation (von Mises instantaneous yield criterion). The experimental results also reveal that the friction mechanism at the controlled flank-wear contact area is essentially the same as that occurring at the tool face. The difference in behavior of the two steels was attributed to the role that manganese sulfide appears to play in free-cutting steels.

The Effect of Cold-Drawing on the Yield and Flow Behaviour of OFHC Copper under Combined Stress

1979 ◽  
Vol 21 (4) ◽  
pp. 235-245 ◽  
Author(s):  
G. Holloway ◽  
A. Shelton
Keyword(s):  
Internal Pressure ◽  
Yield Criterion ◽  
Creep Behaviour ◽  
Cold Drawing ◽  
Ofhc Copper ◽  
Axial Tension ◽  
Material Creep ◽  
Yield Loci ◽  
Tresca Criterion ◽  
Good Agreement

Tests under combinations of tension, torsion and internal pressure have been performed at constant stress ratio on oxygen-free high-conductivity (OFHC) copper, previously annealed and then subjected to progressive reductions in the plug-drawing process. The influence of cold-drawing was investigated by means of six reductions in area up to 81 per cent and this showed marked changes in the creep behaviour. Logarithmic creep no longer occurred and, in contrast to the annealed material, creep was observed at stresses well below yield when the latter is defined by the backward extrapolation method. The creep rate accelerated rapidly as the yield stress was approached and the creep strain became large compared with the instantaneous strain. Under axial tension—internal pressure, symmetrical yield loci tending progressively towards the Tresca criterion were found for reductions up to 42.4 per cent. Asymmetry developed at the largest reduction and, in general, the normality rule was obeyed in subsequent plastic strain behaviour for all tests. Under axial tension—torsion and internal pressure—torsion, almost identical elliptical yield loci were found for each reduction. These also tended towards the Tresca criterion for reductions up to 42.4 per cent and distortion was only observed at the largest reduction. Again, the normality rule was obeyed. Yield criteria derived from the theory of Edelman and Drucker were in good agreement with experiment over all yield loci. Hill's theory showed good agreement with experiment under tension—torsion, except for the largest reduction, but was inadequate for those axial tension—internal pressure tests not in agreement with the Maxwell–Mises yield criterion.

Elastoplastic analysis of a thin-walled tube under cyclic bending and constant internal pressure: A simplified model

2014 ◽  
Vol 229 (4) ◽  
pp. 591-602 ◽  
Author(s):  
Hosein Yazdani ◽  
Ali Nayebi
Keyword(s):  
Internal Pressure ◽  
Yield Criterion ◽  
Kinematic Hardening ◽  
Elastoplastic Analysis ◽  
Simple Method ◽  
Cyclic Bending ◽  
Mapping Algorithm ◽  
Interaction Diagram ◽  
Present Solution ◽  
Thin Walled

In this study, the elastoplastic analysis of thin-walled tubes under cyclic bending and internal pressure is presented. A simple method is presented and verified. In order to predict ratcheting or shakedown behavior in the cyclic loading, von-Mises yield criterion as the yield surface and Chaboche’s nonlinear kinematic hardening model are used. The stress–strain variation is obtained with the help of return mapping algorithm. The present solution is in good agreement with experimental results. Shakedown or ratcheting behavior of the tube under various combinations of applied constant internal pressure and cyclic curvature is considered, Bree’s interaction diagram is obtained and the boundary between shakedown and ratcheting zone is determined.

Strength Analysis of Coiled Tubing in the Injector

2010 ◽  
Vol 97-101 ◽  
pp. 2720-2723 ◽  
Author(s):  
Zheng Liang ◽  
Huai Xin Mao ◽  
Guang Hui Zhao ◽  
Fa Guang Jiang
Keyword(s):  
Stress State ◽  
Axial Force ◽  
Yield Criterion ◽  
Strength Analysis ◽  
Yield Limit ◽  
Coiled Tubing ◽  
Inner Pressure ◽  
Gripping Force ◽  
Force Pressure ◽  
Sinusoidal Function

Coiled tubing (CT) injector head is a key part of CT unit. Friction between gripper blocks and CT offers axial force that runs and retrieves the CT into or out of the wellbore. The CT held by the gripper blocks is loaded by axial force, pressure of inner fluid and gripping force, and is in a complex forcing state. Here it was assumed that all stresses were invariable longitudinally and could be simplified as problem of plane strain. The gripping force acted on the outer surface of CT was set as sinusoidal function along circumference. Stress function was employed to deduce the stress state of CT in gripper blocks. The effects of gripping force, inner pressure and axial force on CT strength were studied, and yield limit curves of the CT were presented by Mises yield criterion. These results offer referring data for minimizes the risk of scarring or mashing the CT.

Bending Capacity Analyses of Corroded Pipelines

2009 ◽  
Author(s):  
Weiwei Yu ◽  
Pedro M. Vargas ◽  
Dale G. Karr
Keyword(s):  
Internal Pressure ◽  
Carrying Capacity ◽  
Full Scale ◽  
Experimental Results ◽  
Secondary Effects ◽  
Moment Capacity ◽  
Bend Testing ◽  
Bending Capacity ◽  
Point Bend

Appendix G of the ASME B31 pipeline and piping codes addresses the pressure containment capacity of pipelines and vessels with locally corroded sections. However, the ability of corroded sections to carry moment, for example in thermal loops, is not addressed in fitness-for-service codes today. This paper presents nonlinear FEA and full-scale 4-point-bend testing of pipes with locally-thinned-areas (LTAs) to simulate corrosion. The LTAs are loaded in compression, and the buckle moment is used as the carrying capacity of the corroded section. The nonlinear FEA is found to match the experimental results, validating this methodology for computing moment capacity in corroded sections. Significant secondary effects were found to affect the testing results. This paper identifies and quantifies these effects. Also, somewhat contrary to intuition, internal pressure is demonstrated to adversely affect the bending capacity for the intermediate-low D/t ratio (17.25) pipe tested.

Effects of the Yield Criterion on Predicted Fracture Responses of Pipelines Subjected to Large Plastic Deformation With and Without Internal Pressure

2010 ◽  
Author(s):  
Alexandre Kane ◽  
Erling O̸stby ◽  
Odd-Geir Lademo ◽  
Torodd Berstad ◽  
Odd Sture Hopperstad
Keyword(s):  
Internal Pressure ◽  
Yield Surface ◽  
Structural Integrity ◽  
Yield Criterion ◽  
Surface Shape ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Safety Level ◽  
Standard Material ◽  
Von Mises

The structural integrity of offshore pipelines is of vital importance for safe oil and gas transport. To ensure the required safety level, non-linear Finite Element (FE) analyses are necessary to perform fracture assessment of pipes under various, realistic loading conditions. Many standard material models, as found in commercial FE codes, pre-suppose the yield criterion of von Mises. This choice provides in many cases reasonable accuracy, certainty and engineering designs, but for some materials and application areas, it is much too inaccurate. In this work, 3D elastic–plastic FE simulations of pipes with internal surface cracks have been carried out. The aim of the work is to evaluate the influence of the yield criterion on the predicted fracture response. Analyses are performed on pipes loaded in tension, with and without internal pressure. The model shows that the yield surface shape may have a significant effect on the predicted evolution of Crack Tip Opening Displacement (CTOD). If the internal pressure is weak, a reduction in strain capacity is observed when the yield surface shape is varied from the rounded von Mises towards the cornered Tresca-like yield surface.

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