Theoretical and Numerical Predictions of Burst Pressure of Pipelines

2007 ◽  
Vol 129 (4) ◽  
pp. 644-652 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Brian N. Leis
Keyword(s):  
Equivalent Stress ◽  
Failure Criteria ◽  
Burst Pressure ◽  
Isotropic Hardening ◽  
Flow Rule ◽  
Strain Criterion ◽  
Stress Criterion ◽  
Numerical Predictions ◽  
Yield Theory ◽  
Von Mises

To accurately characterize plastic yield behavior of metals in multiaxial stress states, a new yield theory, i.e., the average shear stress yield (ASSY) theory, is proposed in reference to the classical Tresca and von Mises yield theories for isotropic hardening materials. Based on the ASSY theory, a theoretical solution for predicting the burst pressure of pipelines is obtained as a function of pipe diameter, wall thickness, material hardening exponent, and ultimate tensile strength. This solution is then validated by experimental data for various pipeline steels. According to the ASSY yield theory, four failure criteria are developed for predicting the burst pressure of pipes by the use of commercial finite element softwares such as ABAQUS and ANSYS, where the von Mises yield theory and the associated flow rule are adopted as the classical metal plasticity model for isotropic hardening materials. These failure criteria include the von Mises equivalent stress criterion, the maximum principal stress criterion, the von Mises equivalent strain criterion, and the maximum tensile strain criterion. Applications demonstrate that the proposed failure criteria in conjunction with the ABAQUS or ANSYS numerical analysis can effectively predict the burst pressure of end-capped line pipes.

Theoretical and Numerical Predictions of Burst Pressure of Pipelines

2006 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Brian N. Leis
Keyword(s):  
Failure Criteria ◽  
Burst Pressure ◽  
Flow Rule ◽  
Strain Criterion ◽  
Stress Criterion ◽  
Finite Element Software ◽  
Numerical Predictions ◽  
Associate Flow Rule ◽  
Yield Theory ◽  
Von Mises

It is known that the Tresca yield theory predicts a lower bound of burst pressure, whereas the von Mises yield theory provides an upper bound of burst pressure of pipelines. To accurately predict the burst pressure, the present authors [1] recently developed a new multiaxial yield theory for isotropic hardening materials, based on an average shear stress criterion (ASSC). Extensive classic experiments showed that the ASSC criterion can well correlate the stress-strain relations for both initial yield and subsequent yield states. Based on the ASSC yield theory, a new theoretical solution of the burst pressure of pipelines at plastic collapse is developed as a function of pipe geometry, material hardening exponent, and ultimate tensile strength. This solution is then validated by experimental data for various pipeline steels. The ASSC yield theory is further applied to accurately determine actual burst pressure using available finite element software like ABAQUS, which currently adopts the von Mises yield criterion and the associate flow rule for isotropic elastic-plastic analysis. Four burst failure criteria: the Mises equivalent stress criterion, the maximum principal stress criterion, the Mises equivalent strain criterion and the maximum tensile strain criterion are developed as functions of the ultimate tensile stress and the strain hardening exponent. Application demonstrates that the proposed failure criteria in conjunction with ABAQUS numerical analysis can accurately determine burst pressure of pipelines.

Evaluations of failure initiation criteria for predicting damages of composite structures under crushing loading

2018 ◽  
Vol 37 (21) ◽  
pp. 1279-1303 ◽  
Author(s):  
Hongyong Jiang ◽  
Yiru Ren ◽  
Zhihui Liu ◽  
Songjun Zhang ◽  
Xiaoqing Wang
Keyword(s):  
Composite Structures ◽  
Maximum Stress ◽  
Failure Modes ◽  
Damage Model ◽  
Axial Loading ◽  
Failure Criteria ◽  
Quantitative Relation ◽  
Stress Criterion ◽  
Failure Initiation ◽  
Numerical Predictions

The crushing behaviors of thin-walled composite structures subjected to quasi-static axial loading are comparatively evaluated using four different failure initiation criteria. Both available crushing tests of composite corrugated plate and square tube are used to validate the stiffness degradation-based damage model with the Maximum-stress criterion. Comparatively, Hashin, Maximum-stress, Stress-based Linde, and Modified criteria are respectively implemented in the damage model to predict crush behaviors of corrugated plate and square tube. To develop failure criteria, effects of shear coefficients and exponents in the Modified and Maximum-stress criteria on damage mechanisms of corrugated plate are discussed. Results show that numerical predictions successfully capture both of experimental failure modes and load–displacement responses. The Modified criterion and particularly Maximum-stress criterion are found to be more appropriate for present crush models of corrugated plate and square tube. When increasing the failure index, the crushing load is decreased, which also causes premature material failure. The shear coefficient and exponents have dramatic influence on the crushing load. Overall, an insight into the quantitative relation of failure initiation is obtained.

Failure phenomena in metallic and metal-lined polymer composite pressure vessels for aerospace applications

2021 ◽  
Author(s):  
Goldin Priscilla C P ◽  
Selwin Rajadurai J
Keyword(s):  
Polymer Composite ◽  
Local Coordinate System ◽  
Failure Criteria ◽  
Pressure Vessels ◽  
Burst Pressure ◽  
Ansys Software ◽  
Stress Criterion ◽  
Aerospace Applications ◽  
Solution Convergence ◽  
Composite Pressure Vessels

Metallic and metal-lined polymer composite pressure vessels are extensively used in industries including aerospace. In the absence of unique failure criteria for the structural elements, phenomenological or empirical methodologies always fascinate the researchers. This paper deals with comprehensive methodologies in the prediction of burst pressure of metallic and metal-lined polymer composite pressure vessels for aerospace applications. Metallic pressure vessels are analyzed using Ansys software considering the elastic-plastic nature of materials. The progressive analysis is carried out in metal-lined composite pressure vessels in an explicit mode using Ansys software. The problem of solution convergence is discussed in detail. The extent of degradation in static analysis is suggested after multiple analysis trials. In the unit pressure extrapolation technique, stress components are evaluated using Ansys software, transformed into the local coordinate system and hence failure pressure of the first ply is identified by maximum stress criterion. Then the analysis is continued with degrading of failed layers using Ansys software and successive failures of layers are identified in steps. The results of burst pressure, evaluated through the present analyses show good agreement with the published test results. The procedures described in the paper would be of interest to the designers of pressure vessels.

Finite Element Analysis of Burst Pressure for Pipelines With Long Corrosion Defects

2012 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Brian N. Leis
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Failure Criterion ◽  
Equivalent Stress ◽  
Theoretical Solution ◽  
Burst Pressure ◽  
Element Analysis ◽  
Integrity Assessment ◽  
Corrosion Defects ◽  
Von Mises

Plastic collapse analysis and remaining burst strength determination are critical to a corroded pipeline in its fitness-for-service analysis and integrity assessment. For very long corrosion defects, the present authors proposed a theoretical solution for predicting the burst pressure of corroded pipe in terms of a newly developed average shear stress yield theory, and validated it using full-scale burst data for long real corrosion defects. This paper then presents a finite element analysis (FEA) procedure to determine the remaining burst pressure for a very long blunt defect. A burst failure criterion that is referred to as von Mises equivalent stress criterion is proposed first in reference to the von Mises theory. Detailed elastic-plastic FEA calculations are performed using ABAQUS for a series of corroded pipes with infinitely long defects in different widths. From the FEA results and using the proposed failure criterion, the numerical results of burst pressure are determined for the long defects. The results show that using the proposed failure criterion, the FEA simulation can accurately determine the burst pressure for corroded pipes with long defects that is consistent with the theoretical solution. The conventional assessment methods including ASME B31G, RSTRENG, PCORRC and LPC are also evaluated and discussed in comparison with the proposed theoretical solution of burst pressure for long corrosion defects.

An Experimental Investigation Into the Plastic Flow and Strain Hardening of Mild Steel Under Proportional and Abruptly Changing Deformation Paths at a Controlled Rate

1983 ◽  
Vol 105 (3) ◽  
pp. 147-154 ◽  
Author(s):  
S. A. Meguid ◽  
L. E. Malvern
Keyword(s):  
Plastic Strain ◽  
Equivalent Stress ◽  
Equivalent Plastic Strain ◽  
Plastic Strain Rate ◽  
Isotropic Hardening ◽  
Rate Vector ◽  
Vector Direction ◽  
Von Mises Equivalent Stress ◽  
Strain Rate Vector ◽  
Von Mises

Tension-torsion tests are reported on thin-walled tubes up to strains of the order of five percent. Attention was given to the question of whether, as has been suggested, in the continued loading after a sudden direction change in the deformation path, the behavior of the material quickly approaches that predicted by a von Mises plastic potential and isotropic hardening. The results show a slower approach of the deviatoric stress vector direction to the plastic strain-rate vector direction than had been expected, as well as considerable variations in the von Mises equivalent stress versus equivalent plastic strain curves.

On isotropy and anisotropy in the theory of plasticity

1982 ◽  
Vol 383 (1785) ◽  
pp. 333-357 ◽  
Keyword(s):  
Plastic Strain ◽  
Kinematic Hardening ◽  
Deformation Behaviour ◽  
Constitutive Relations ◽  
Equivalent Stress ◽  
Isotropic Hardening ◽  
Flow Rule ◽  
Yield Functions ◽  
Strain Paths ◽  
Cross Hardening

Test results on the plastic behaviour of a range of engineering metals and alloys under proportionate loading are examined in terms of the isotropic hardening rule with homogeneous yield functions of the form f ( J' 2 , J' 3 ). It is shown that the inclusion of J' 3 accounts for the differences observed between experiment and the Levy-Mises flow rule, that is in the associated constitutive relations, Lode parameter equality and equivalent stress–plastic strain correlations. Non-symmetrical functions account for nonlinear plastic strain paths and the presence of second-order strain under torsional loading. Alternative yield functions are presented where deformation behaviour has been identified with initially anisotropic material. The distinction between isotropic and anisotropic yield functions is clarified by an exami­nation of component plastic strain paths in a tension test. It is shown that anisotropy due to plastic strain can be modelled by combining the rules of isotropic and kinematic hardening. Functions describing the model are consistent with experimental observations in that they display a marked Bauschinger effect and an absence of cross-hardening.

An Analysis of Filament Overwound Toroidal Pressure Vessels and Optimum Design of Such Structures

2002 ◽  
Vol 124 (2) ◽  
pp. 215-222 ◽  
Author(s):  
Shuguang Li ◽  
John Cook
Keyword(s):  
Optimum Design ◽  
Equivalent Stress ◽  
Mechanical Damage ◽  
Stress Rupture ◽  
Optimization Procedure ◽  
Pressure Vessels ◽  
Thickness Variation ◽  
Von Mises Equivalent Stress ◽  
Metal Liner ◽  
Von Mises

This paper is concerned with the membrane shell analysis of filament overwound toroidal pressure vessels and optimum design of such pressure vessels using the results of the analysis by means of mathematical nonlinear programming. The nature of the coupling between overwind and linear has been considered based on two extreme idealizations. In the first, the overwind is rigidly coupled with the liner, so that the two deform together in the meridional direction as the vessel dilates. In the second, the overwind is free to slide relative to the linear, but the overall elongations of the two around a meridian are identical. Optimized designs with the two idealizations show only minor differences, and it is concluded that either approximation is satisfactory for the purposes of vessel design. Aspects taken into account are the intrinsic overwind thickness variation arising from the winding process and the effects of fiber pre-tension. Pre-tension can be used not only to defer the onset of yielding, but also to achieve a favorable in-plane stress ratio which minimizes the von Mises equivalent stress in the metal liner. Aramid fibers are the most appropriate fibers to be used for the overwind in this type of application. The quantity of fiber required is determined by both its short-term strength and its long-term stress rupture characteristics. An optimization procedure for the design of such vessels, taking all these factors into account, has been established. The stress distributions in the vessels designed in this way have been examined and discussed through the examples. A design which gives due consideration of possible mechanical damage to the surface of the overwind has also been addressed.

Shakedown of Torispherical Heads Using Plastic Analysis

1998 ◽  
Vol 120 (4) ◽  
pp. 431-437 ◽  
Author(s):  
A. Kalnins ◽  
D. P. Updike
Keyword(s):  
Equivalent Stress ◽  
Applied Pressure ◽  
Material Behavior ◽  
Parameter Range ◽  
Burst Pressure ◽  
Fatigue Stress ◽  
Stress Parameter ◽  
Hardening Models ◽  
Plastic Analysis ◽  
Definition Of

The condition of shakedown is examined for torispherical heads. The reason for using plastic analysis is to account for the strengthening that heads experience when subjected to internal pressure. Cyclic pressures are considered up to an allowable burst pressure that is based on the membrane stresses of the spherical part of the head. To simulate a proof test before service cycling, cases when the applied pressure is higher for the first cycle are also included. A definition of shakedown is used that places the limit of twice the yield strength on a fatigue stress parameter range that is defined in the paper. The equivalent stress and plastic strain ranges are calculated for ten head thickness-to-spherical radius ratios. From these data, shakedown pressures are obtained as fractions of the allowable burst pressure. By giving bounds for isotropic and kinematic strain-hardening models, the results are made independent from specific cyclic material behavior. It is also shown that if an elastic, geometrically linear algorithm is used, which is unable to account for the strengthening, the fatigue stress parameter range is overestimated for the thinner heads.

Biomechanical Behavior of All-Ceramic Crowns with Variable Thicknesses of Zirconia Frameworks

2016 ◽  
Vol 835 ◽  
pp. 97-102
Author(s):  
Liliana Porojan ◽  
Florin Topală ◽  
Sorin Porojan
Keyword(s):  
Mechanical Behavior ◽  
Equivalent Stress ◽  
The Finite Element Method ◽  
Static Loads ◽  
Biomechanical Behavior ◽  
All Ceramic ◽  
Ceramic Crowns ◽  
Von Mises Equivalent Stress ◽  
Von Mises ◽  
Posterior Restorations

Zirconia is an extremely successful material for prosthetic restorations, offering attractive mechanical and optical properties. It offers several advantages for posterior restorations because it can withstand physiological posterior forces. The aim of the study was to achieve the influence of zirconia framework thickness on the mechanical behavior of all-ceramic crowns using numerical simulation. For the study a premolar was chosen in order to simulate the mechanical behavior in the components of all-ceramic crowns and teeth structures regarding to the zirconia framework thickness. Maximal Von Mises equivalent stress values were recorded in teeth and restorations. Due to the registered maximal stress values it can be concluded that it is indicated to achieve frameworks of at least 0.5 mm thickness in the premolar area. Regarding stress distribution concentration were observed in the veneer around the contact areas with the antagonists, in the framework under the functional cusp and in the oral part overall and in dentin around and under the marginal line, also oral. The biomechanical behavior of all ceramic crowns under static loads can be investigated by the finite element method.

A Note on the Shear Stress Criterion for Fatigue Failure under Combined Stress

1969 ◽  
Vol 20 (1) ◽  
pp. 57-60 ◽  
Author(s):  
R. E. Little
Keyword(s):  
Shear Stress ◽  
Fatigue Limit ◽  
Fatigue Failure ◽  
Failure Criterion ◽  
Basic Problem ◽  
Failure Criteria ◽  
Test Methods ◽  
Combined Stress ◽  
Stress Criterion

SummaryNishihara’s combined bending and torsion out-of-phase fatigue limit data are analysed. The Tresca shear stress failure criterion predicts strengths up to 30 per cent higher than observed. It thus appears that renewed attention should be given to the basic problem of developing reliable combined stress failure criteria. It is suggested that new test methods will be required for this purpose.

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