Bauschinger Effect Design Procedures for Compound Tubes Containing an Autofrettaged Layer

2000 ◽  
Vol 123 (2) ◽  
pp. 203-206 ◽  
Author(s):  
Anthony P. Parker
Keyword(s):  
Bauschinger Effect ◽  
Design Procedure ◽  
External Pressure ◽  
Pressure Vessels ◽  
Design Procedures ◽  
Shrink Fitting ◽  
Stress Profiles ◽  
Hoop Stresses ◽  
Shrink Fit ◽  
Outside Diameter

Autofrettage is used to introduce advantageous residual stresses into pressure vessels. The Bauschinger effect can produce less compressive residual hoop stresses near the bore than are predicted by “ideal” autofrettage solutions. A design procedure was recently proposed which models material removal from the bore or outside diameter of a single, plain autofrettaged tube in the presence of Bauschinger effect. This paper extends the procedure to model the addition of pressure or of material (via shrink-fit) to the tube, providing associated residual stress profiles following various amounts of further yielding due to a net external pressure. Simple criteria are developed for determining, and avoiding, further yielding in the autofrettaged tube when it is used as part of a compound assembly involving shrink-fitting; these criteria are based upon net pressure differential between the bore and outside diameter of the autofrettaged tube. An alternative criterion, based upon bore hoop stress, is shown to be erroneous.

Bauschinger Effect’ Influence on the Componud Cylinder Containing an Autofrettaged Layer

2007 ◽  
Vol 345-346 ◽  
pp. 149-152 ◽  
Author(s):  
Young Shin Lee ◽  
Jae Hyun Park ◽  
Jae Hoon Kim ◽  
Ki Up Cha ◽  
Suk Kyun Hong
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Bauschinger Effect ◽  
External Pressure ◽  
The Finite Element Method ◽  
Compound Cylinder ◽  
Shrink Fitting ◽  
Stress Profiles ◽  
Hoop Stresses

Autofrettage is used to introduce advantageous residual stresses into cylinders. The Bauschinger effect can produce less compressive residual hoop stresses near the bore than are predicted “ideal” autofrettage solutions. A723 steel is used for compound cylinder. This paper extends the analysis to material the addition of pressure or of shrink-fitting to the cylinders, providing associated residual stress profiles following various amounts of further yielding due to a net external pressure. The Bauschinger effects for “realistic” – Bauschinger effect dependent autofrettage are obtained. The 2-D analysis is performed via the finite element method. The Bauschinger effect is found to significantly lower the beneficial stress due to autofrettage.

Residual Stresses and Lifetimes of Tubes Subjected to Shrink Fit Prior to Autofrettage

2003 ◽  
Vol 125 (3) ◽  
pp. 282-286 ◽  
Author(s):  
Anthony P. Parker ◽  
David P. Kendall
Keyword(s):  
Material Removal ◽  
Hoop Stress ◽  
Bauschinger Effect ◽  
External Pressure ◽  
Fatigue Lifetime ◽  
Shrink Fitting ◽  
Plain Tube ◽  
Specific Geometry ◽  
Shrink Fit ◽  
Summary Data

There is increasing interest in the use of compound cylinders that combine shrink fit and autofrettage, taking account of Bauschinger effect. Previous work has analyzed material removal from a plain, autofrettaged cylinder and the application of an external pressure or shrink to a previously autofrettaged plain tube. In this paper a different design philosophy is examined, namely the shrink fitting of two tubes prior to autofrettage. Such a process is shown to be beneficial in inhibiting loss of near-bore compressive residual hoop stress due to Bauschinger effect and thereby increasing calculated fatigue lifetime. These effects are described in detail for a specific geometry, and summary data suitable for use by designers are presented for a large range of configurations.

Design Optimization of Compound Cylinders Subjected to Autofrettage and Shrink-Fitting Processes

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Ossama R. Abdelsalam ◽  
Ramin Sedaghati
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Finite Element Model ◽  
Design Optimization ◽  
Element Model ◽  
Pressure Vessels ◽  
Stress Profile ◽  
Shrink Fitting ◽  
Shrink Fit ◽  
Optimal Configurations

The autofrettage and shrink-fit processes are used to increase the load bearing capacity and fatigue life of the pressure vessels under thermomechanical loads. In this paper, a design optimization methodology has been proposed to identify optimal configurations of a two-layer cylinder subjected to different combinations of shrink-fit and autofrettage processes. The objective is to find the optimal thickness of each layer, autofrettage pressure and radial interference for each shrink-fit, and autofrettage combination in order to increase the fatigue life of the compound cylinder by maximizing the beneficial and minimizing the detrimental residual stresses induced by these processes. A finite element model has been developed in ansys environment to accurately evaluate the tangential stress profile through the thickness of the cylinder. The finite element model is then utilized in combination with design of experiment (DOE) and the response surface method (RSM) to develop a smooth response function which can be effectively used in the design optimization formulation. Finally, genetic algorithm (GA) combined with sequential quadratic programming (SQP) has been used to find global optimum configuration for each combination of autofrettage and shrink-fit processes. The residual stress distributions and the mechanical fatigue life based on the ASME code for high pressure vessels have been calculated for the optimal configurations and then compared. It is found that the combination of shrink-fitting of two base layers then performing double autofrettage (exterior autofrettage prior to interior autofrettage) on the whole assembly can provide higher fatigue life time for both inner and outer layers of the cylinder.

Full Thermal Simulation of an Arbitrary, Plane Axisymmetric Residual Stress Field

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Anthony P. Parker
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Pressure Vessels ◽  
Thermal Simulation ◽  
Residual Stress Field ◽  
Subsequent Determination ◽  
Arbitrary Plane ◽  
Stress Profiles ◽  
Hoop Stresses

Abstract In this paper, numerical formulations are presented; these permit full thermal simulation of an arbitrary plane axisymmetric residual stress field encompassing hoop, radial, and axial stresses. Earlier formulations were based upon the determination of a temperature profile within the tube that could only replicate radial and hoop stresses; in general, axial stresses were incorrect. This new thermal simulation provides all three stresses and is achieved by incorporating orthotropic coefficients of thermal expansion that themselves vary with radius. Results are generally highly accurate. Crucial near-bore hoop and axial stresses can be replicated within 1%. Near-bore behavior is discussed in detail. These formulations will permit subsequent determination of stress intensity factors (SIF) for arbitrarily orientated cracks within pressure vessels in the presence of pre-existing residual stresses. Note that these thermal solutions mimic known, residual stress profiles; they do not predict residual stress profiles.

Analysis of Stress Concentrations in Thick Cylinders With Sideholes and Crossholes

1972 ◽  
Vol 94 (3) ◽  
pp. 815-824 ◽  
Author(s):  
J. C. Gerdeen
Keyword(s):  
Stress Concentration ◽  
Stress Concentrations ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Experimental Values ◽  
Pressure Stress ◽  
Shrink Fit ◽  
Outside Diameter ◽  
Theoretical Results

An approximate theoretical analysis is presented for the determination of stress concentration factors in thick walled cylinders with sideholes and crossholes. The cylinders are subjected to both internal pressure and external shrink-fit pressure. Stress concentration factors are plotted as functions of the geometrical ratios of outside diameter-to-bore diameter, and bore diameter-to-sidehole diameter. Theoretical results are compared to experimental values available in the literature and results of experiments described in a separate paper.

Use of Duplex Stainless Steel in Economic Design of a Pressure Vessel

2006 ◽  
Vol 129 (1) ◽  
pp. 155-161 ◽  
Author(s):  
Milan Veljkovic ◽  
Jonas Gozzi
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Stainless Steels ◽  
Pressure Vessel ◽  
Design Procedure ◽  
High Strength Steels ◽  
High Strength ◽  
Pressure Vessels ◽  
Economic Design ◽  
European Standard

Pressure vessels have been used for a long time in various applications in oil, chemical, nuclear, and power industries. Although high-strength steels have been available in the last three decades, there are still some provisions in design codes that preclude a full exploitation of its properties. This was recognized by the European Equipment Industry and an initiative to improve economy and safe use of high-strength steels in the pressure vessel design was expressed in the evaluation report (Szusdziara, S., and McAllista, S., EPERC Report No. (97)005, Nov. 11, 1997). Duplex stainless steel (DSS) has a mixed structure which consists of ferrite and austenite stainless steels, with austenite between 40% and 60%. The current version of the European standard for unfired pressure vessels EN 13445:2002 contains an innovative design procedure based on Finite Element Analysis (FEA), called Design by Analysis-Direct Route (DBA-DR). According to EN 13445:2002 duplex stainless steels should be designed as a ferritic stainless steels. Such statement seems to penalize the DSS grades for the use in unfired pressure vessels (Bocquet, P., and Hukelmann, F., 2001, EPERC Bulletin, No. 5). The aim of this paper is to present an investigation performed by Luleå University of Technology within the ECOPRESS project (2000-2003) (http://www.ecopress.org), indicating possibilities towards economic design of pressure vessels made of the EN 1.4462, designation according to the European standard EN 10088-1 Stainless steels. The results show that FEA with von Mises yield criterion and isotropic hardening describe the material behaviour with a good agreement compared to tests and that 5% principal strain limit is too low and 12% is more appropriate.

Elastic analysis of exponential FGM disks subjected to internal and external pressure

2013 ◽  
Vol 3 (3) ◽  
Author(s):  
Mohammad Nejad ◽  
Majid Abedi ◽  
Mohammad Lotfian ◽  
Mehdi Ghannad
Keyword(s):  
Radial Direction ◽  
Circumferential Stress ◽  
External Pressure ◽  
Functionally Graded ◽  
Elastic Analysis ◽  
The Finite Element Method ◽  
Graded Materials ◽  
Material Inhomogeneity ◽  
Closed Form Analytical Solution ◽  
Stress Profiles

AbstractAssuming exponential varying properties in the radial direction and constant Poisson’s ratio, a closed-form analytical solution based on the elasticity theory is obtained to elastic analysis of disks made of functionally graded materials (FGMs) subjected to internal and external pressure. Following this, radial displacement, radial stress, and circumferential stress profiles are plotted for different values of material inhomogeneity constant, as a function of radial direction. The displacements and stresses distributions are compared with the solutions of the finite element method (FEM) and comparison with the corresponding numerical solution indicates that the proposed solution has excellent convergence and accuracy.

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