Experimental and Numerical Analysis of Ratcheting Behavior of SS 316 L Thin-Walled Pipes Subjected to Cyclic Internal Pressure

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
R. Karimi ◽  
M. Shariati
Keyword(s):  
Internal Pressure ◽  
Kinematic Hardening ◽  
Pressure Amplitude ◽  
Steel Pipes ◽  
Ratcheting Strain ◽  
Mean Pressure ◽  
Thin Walled Pipe ◽  
Thin Walled ◽  
Hoop Direction ◽  
Good Agreement

Abstract This paper investigates ratcheting behavior of SS316 L thin-walled steel pipes subjected to cyclic internal pressure experimentally and numerically. Numerical simulations were performed using abaqus software, and nonlinear isotropic/kinematic hardening model. According to experimentations, it was found that the ratcheting strain is only significant in the hoop direction of a pipe subjected to cyclic internal pressure. The effects of pressure amplitude and mean pressure on ratcheting behavior of thin walled pipe in hoop direction were studied experimentally and numerically, and it was observed that increasing the pressure amplitude and mean pressure increased the percentage of ratcheting strain. Another important point about the results was the dominance of pressure amplitude on mean pressure. The results showed that at higher mean pressures the effect of pressure amplitude on increasing the percentage of ratcheting strain was greater. Finally, the experimental and numerical results were in good agreement.

CONTINUUM DAMAGE MECHANICS ANALYSIS OF THIN-WALLED TUBE UNDER CYCLIC BENDING AND INTERNAL CONSTANT PRESSURE

2013 ◽  
Vol 05 (04) ◽  
pp. 1350038 ◽  
Author(s):  
H. YAZDANI ◽  
A. NAYEBI
Keyword(s):  
Internal Pressure ◽  
Damage Mechanics ◽  
Low Cycle Fatigue ◽  
Kinematic Hardening ◽  
Damage Model ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Cyclic Bending ◽  
Thin Walled Tube ◽  
Thin Walled

Ratcheting and fatigue damage of thin-walled tube under cyclic bending and steady internal pressure is studied. Chaboche's nonlinear kinematic hardening model extended by considering the effect of continuum damage mechanics employed to predict ratcheting. Lemaitre damage model [Lemaitre, J. and Desmorat, R. [2005] Engineering Damage Mechanics (Springer-Verlag, Berlin)] which is appropriate for low cyclic loading is used. Also the evolution features of whole-life ratcheting behavior and low cycle fatigue (LCF) damage of the tube are discussed. A simplified method related to the thin-walled tube under bending and internal pressure is used and compared well with experimental results. Bree's interaction diagram with boundaries between shakedown and ratcheting zone is determined. Whole-life ratcheting of thin-walled tube reduces obviously with increase of internal pressure.

Lateral Loading of Internally Pressurized Steel Pipes

2005 ◽  
Author(s):  
S. A. Karamanos ◽  
K. P. Andreadakis ◽  
A. M. Gresnigt
Keyword(s):  
Internal Pressure ◽  
Test Results ◽  
Steel Pipes ◽  
End Conditions ◽  
Pressure Tubes ◽  
Nonlinear Shell ◽  
Numerical Tools ◽  
Model Equations ◽  
Device Size ◽  
Good Agreement

The paper examines the denting response of tubular members and pipes subjected to lateral (transverse) quasi-static loading, in the presence of internal pressure. Tubes are modeled with nonlinear shell finite elements, and the numerical results are in good agreement with available experimental data. Using the numerical tools, a parametric study is conducted to examine the effects of pressure level, as well as those of denting device size and pipe end conditions. It is mainly concluded that for a given denting displacement, the presence of internal pressure increases significantly the corresponding denting force. A simplified two-dimensional heuristic model is also adopted, which yields closed-form expressions for the denting force. The model equations are in fairly good agreement with the test results and illustrate pipe denting response in an elegant manner.

scholarly journals Prediction of actual limit stresses in a thin-walled pipe loaded with internal pressure and axial tension

2021 ◽  
pp. 35-41
Author(s):  
Halyna Kozbur ◽  
Oleh Shkodzinsky ◽  
Oleh Yasniy ◽  
Ihor Kozbur ◽  
Roman Hrom'yak
Keyword(s):  
Internal Pressure ◽  
Limit State ◽  
Physical And Mechanical Properties ◽  
Correct Prediction ◽  
Plastic Deformation Zone ◽  
Limit Values ◽  
Axial Tension ◽  
Thin Walled Pipe ◽  
True Stresses ◽  
Thin Walled

If a thin-walled pipe loaded with internal pressure and tension allows the appearance of plastic trains, then the uniform plastic stability loss with the emergence of a local plastic deformation zone is considered the limit state, the corresponding stresses are considered as the limit. Correct prediction of the stress-strain state at the moment of strain localization requires taking into account the actual size of the loaded pipe and the calculation of true stresses. The article proposes the implementation of the method of predicting the limit values of true stresses that appear in the pipe at different ratios of internal pressure and axial tension. The physical and mechanical properties of the material, the type of stress state and the change in the actual dimensions of the loaded element are taken into account.

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.

On torsional stiffness and natural frequency of bellows

2004 ◽  
Vol 218 (3) ◽  
pp. 263-271 ◽  
Author(s):  
C L Lu ◽  
T X Wu ◽  
J G Yu ◽  
Q T Ye
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Integration Method ◽  
Torsional Stiffness ◽  
Fe Model ◽  
Expansion Joint ◽  
Pipe Model ◽  
Thin Walled Pipe ◽  
Thin Walled ◽  
Good Agreement

Simplified formulae for torsional natural frequencies of bellows are developed using an equivalent thin-walled pipe model. To do this the torsional stiffness of bellows needs to be worked out. The torsional stiffness of bellows is determined using Chien's integration method. Accordingly, the Expansion Joint Manufactures Association (EJMA) formula for torsional stiffness calculation is modified using two different equivalent radii. The torsional natural frequencies of bellows are calculated using the simplified formulae based on the equivalent thin-walled pipe model and the modified formulae for torsional stiffness of bellows. The results from the simplified formuale are verified by those from a finite element (FE) model and good agreement is shown between the simplified formulae and the FE model.

Ratcheting, Wrinkling and Collapse of Tubes Induced by Axial Cycling Under Internal Pressure

2011 ◽  
Author(s):  
Rong Jiao ◽  
Stelios Kyriakides
Keyword(s):  
Cyclic Loading ◽  
Internal Pressure ◽  
Kinematic Hardening ◽  
Cyclic Plasticity ◽  
Combined Loads ◽  
Offshore Pipeline ◽  
Number Of Cycles ◽  
Cyclic Plasticity Model ◽  
Cycles To Failure ◽  
Good Agreement

A buried offshore pipeline is essentially axially constrained by the soil cover. Heating by the passage of hot oil at high pressure can plastically deform it. The deformation involves expansion of the diameter, which for thinner pipes can be accompanied by axisymmetric wrinkling. During a lifetime of 20 or more years, lines experience regular startup and shutdown cycles. This study examines how this cycling affects wrinkling and the hoop expansion of such lines. A set of experiments on super-duplex tubes with D/t of 28.5 was conducted using the following idealized cyclic loading history. A tube is first pressurized and then compressed into the plastic range to a level that initiates wrinkling. It is then cycled under stress control about a compressive mean stress while the pressure is kept constant. The combined loads cause simultaneous ratcheting in the hoop and axial directions as well as a gradual growth of the wrinkles. At some stage the amplitude of the wrinkles starts to grow exponentially with the number of cycles N leading to localization and collapse. The rate of ratcheting and the number of cycles to failure depend on the initial compressive pre-strain, the internal pressure and the stress cycle parameters. The problem is modeled as a shell with initial axisymmetric imperfections. A challenge in the simulations is that the cyclic plasticity model that is used must be capable of capturing correctly the type of biaxial material ratcheting that develops. The Dafalias-Popov two-surface nonlinear kinematic hardening model, enhanced and suitably calibrated is shown to capture the prevalent ratcheting deformations correctly leading to predictions that are in good agreement with the experimental results. The model is then used to evaluate the ratcheting behavior of pipes under thermal-pressure cyclic loading histories seen by buried pipelines.

scholarly journals Ratcheting Simulation of a Steel Pipe with Assembly Parts under Internal Pressure and a Cyclic Bending Load

2019 ◽  
Vol 9 (23) ◽  
pp. 5025
Author(s):  
Yang ◽  
Dai ◽  
He
Keyword(s):  
Internal Pressure ◽  
Kinematic Hardening ◽  
Three Dimensional ◽  
Bending Moment ◽  
Element Model ◽  
Steel Pipe ◽  
Cyclic Bending ◽  
Ratcheting Strain ◽  
Bending Load ◽  
Transition Points

The ratcheting behavior of a steel pipe with assembly parts was examined under internal pressure and a cyclic bending load, which has not been seen in previous research. An experimentally validated and three dimensional (3D) elastic-plastic finite element model (FEM)—with a nonlinear isotropic/kinematic hardening model—was used for the pipe’s ratcheting simulation and considered the assembly contact effects outlined in this paper. A comparison of the ratcheting response of pipes with and without assembly parts showed that assembly contact between the sleeve and pipe suppressed the ratcheting response by changing its trend. In this work, the assembly contact effect on the ratcheting response of the pipe with assembly parts is discussed. Both the assembly contact and bending moment were found to control the ratcheting response, and the valley and peak values of the hoop ratcheting strain were the transition points of the two control modes. Finally, while the clearance between the sleeve and the pipe had an effect on the ratcheting response when it was not large, it had no effect when it reached a certain value.

Biaxial Ratcheting Under Strain or Stress-Controlled Axial Cycling With Constant Hoop Stress

1994 ◽  
Vol 61 (2) ◽  
pp. 422-428 ◽  
Author(s):  
Z. Xia ◽  
F. Ellyin
Keyword(s):  
Hoop Stress ◽  
304 Stainless Steel ◽  
Test Results ◽  
Cyclic Tests ◽  
Stress Memory ◽  
Qualitative And Quantitative ◽  
Thin Walled ◽  
Tubular Specimens ◽  
Hoop Direction ◽  
Good Agreement

Strain or stress-controlled tension-compression cyclic tests were conducted on pressurized thin-walled tubular specimens of 304 stainless steel. In strain-controlled mode ratcheting strains in hoop direction, and under stress-controlled mode ratcheting in both hoop and axial directions, were observed. To predict the observed ratcheting behavior, an additional evolution rule for the stress memory surface has been introduced in the constitutive model developed recently by the authors. Qualitative and quantitative comparisons with the test results indicate a fairly good agreement in predicting ratcheting deformations.

scholarly journals Numerical prediction of the strength of a thin-walled pipe loaded with internal pressure and axial tension taking into account its actual dimensions

2020 ◽  
Vol 100 (4) ◽  
pp. 11-19
Author(s):  
Halyna Kozbur ◽  
Oleh Shkodzinsky ◽  
Lesia Dmytrotsa
Keyword(s):  
Internal Pressure ◽  
Limit State ◽  
Correct Prediction ◽  
Plastic Deformation Zone ◽  
Limit Values ◽  
Axial Tension ◽  
Thin Walled Pipe ◽  
True Stresses ◽  
Thin Walled ◽  
Actual Geometry

If a thin-walled pipe loaded with internal pressure and tension allows the appearance of plastic strains takes place, then the uniform plastic stability loss with the emergence of a local plastic deformation zone is considered the limit state, the corresponding stresses are considered as the limit ones. Correct prediction of the stress-strain state at the moment of strain localization requires taking into account the actual size of the loaded pipe and the calculation of true stresses. The article proposes the implementation of the method of predicting the limit values of true stresses that appear in the pipe at different ratios of internal pressure and axial tension. The physical and mechanical properties of the material, the type of stress state and the change in the actual dimensions of the loaded pipe are taken into account. For two grades of steels (carbon steel 45 and alloy steel 10MnН2MoV), an increase in the calculated strength threshold is shown with an insignificant additional load of a pipe loaded with pressure and axial tension. Analysis of the results showed that it is possible to establish a balance between the actual geometry of the element and the load, which will solve the problem of finding the optimal ratio of «weight-strength», important for practical applications in aircraft, rocket and mechanical engineering. The proposed method for finding the limiting values of actual stresses makes it possible to calculate a realistic safety factor and make improved engineering solutions at the design and operation stages of structural elements; to increase the efficiency and safety of using pipeline and shell-type saving systems.

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