Analysis of Strength and Residual Stresses in Filament Reinforced Aluminum Cylinders

1975 ◽  
Vol 97 (3) ◽  
pp. 192-198
Author(s):  
F. A. Simonen ◽  
N. C. Henderson ◽  
R. D. Winegardner ◽  
K. Specht
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Relative Increase ◽  
Burst Pressure ◽  
Experimental Measurements ◽  
Gas Cylinder ◽  
Proof Testing ◽  
Gas Cylinders

This paper describes a study of aluminum gas cylinders used in underwater manned vehicles. A determination was made of the relative increase in one cycle burst pressure and fatigue life of an existing aluminum gas cylinder when the sidewall was reinforced with fiberglass overwrap and prestressed by over pressurization. Detailed finite-element stress analyses were conducted to determine the operating stresses and also the residual stresses at the end cap-to-cylinder transition section which were a result of plastic deformation during proof testing. Calculated residual stresses were found to be consistent with experimental measurements. It was determined that the filament reinforcement both increased the vessel burst pressure and increased the vessel fatigue life through favorable prestress effects. Results of vessel fatigue and burst tests are presented and are compared with the predicted performance characteristics.

Effect of Residual Stress or Plastic Deformation History on Fatigue Life Simulation of Pipeline Dents

2018 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Rick Wang
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Strain History ◽  
Deformation History ◽  
Stress Strain ◽  
Element Analysis ◽  
Fea Model

Mechanical dents often occur in transmission pipelines, and are recognized as one of major threats to pipeline integrity because of the potential fatigue failure due to cyclic pressures. With matured in-line-inspection (ILI) technology, mechanical dents can be identified from the ILI runs. Based on ILI measured dent profiles, finite element analysis (FEA) is commonly used to simulate stresses and strains in a dent, and to predict fatigue life of the dented pipeline. However, the dent profile defined by ILI data is a purely geometric shape without residual stresses nor plastic deformation history, and is different from its actual dent that contains residual stresses/strains due to dent creation and re-rounding. As a result, the FEA results of an ILI dent may not represent those of the actual dent, and may lead to inaccurate or incorrect results. To investigate the effect of residual stress or plastic deformation history on mechanics responses and fatigue life of an actual dent, three dent models are considered in this paper: (a) a true dent with residual stresses and dent formation history, (b) a purely geometric dent having the true dent profile with all stress/strain history removed from it, and (c) a purely geometric dent having an ILI defined dent profile with all stress/strain history removed from it. Using a three-dimensional FEA model, those three dents are simulated in the elastic-plastic conditions. The FEA results showed that the two geometric dents determine significantly different stresses and strains in comparison to those in the true dent, and overpredict the fatigue life or burst pressure of the true dent. On this basis, suggestions are made on how to use the ILI data to predict the dent fatigue life.

Stress and Fatigue Life Modeling of Cannon Breech Closures Including Effects of Material Strength and Residual Stress

2000 ◽  
Vol 123 (1) ◽  
pp. 150-154
Author(s):  
John H. Underwood ◽  
Michael J. Glennon
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Fatigue Life ◽  
Yield Strength ◽  
Residual Stresses ◽  
Solid Mechanics ◽  
Element Model ◽  
Pressure Vessels ◽  
Material Strength ◽  
Element Analysis

Laboratory fatigue life results are summarized from several test series of high-strength steel cannon breech closure assemblies pressurized by rapid application of hydraulic oil. The tests were performed to determine safe fatigue lives of high-pressure components at the breech end of the cannon and breech assembly. Careful reanalysis of the fatigue life tests provides data for stress and fatigue life models for breech components, over the following ranges of key parameters: 380–745 MPa cyclic internal pressure; 100–160 mm bore diameter cannon pressure vessels; 1040–1170 MPa yield strength A723 steel; no residual stress, shot peen residual stress, overload residual stress. Modeling of applied and residual stresses at the location of the fatigue failure site is performed by elastic-plastic finite element analysis using ABAQUS and by solid mechanics analysis. Shot peen and overload residual stresses are modeled by superposing typical or calculated residual stress distributions on the applied stresses. Overload residual stresses are obtained directly from the finite element model of the breech, with the breech overload applied to the model in the same way as with actual components. Modeling of the fatigue life of the components is based on the fatigue intensity factor concept of Underwood and Parker, a fracture mechanics description of life that accounts for residual stresses, material yield strength and initial defect size. The fatigue life model describes six test conditions in a stress versus life plot with an R2 correlation of 0.94, and shows significantly lower correlation when known variations in yield strength, stress concentration factor, or residual stress are not included in the model input, thus demonstrating the model sensitivity to these variables.

The Effect of Several Finishing Processes on the Fatigue Resistance of Hole Surfaces

1989 ◽  
Vol 111 (1) ◽  
pp. 71-73 ◽  
Author(s):  
M. O. Lai ◽  
A. Y. C. Nee
Keyword(s):  
Surface Roughness ◽  
Plastic Deformation ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Fatigue Resistance ◽  
Radial Direction ◽  
Fatigue Loading ◽  
Steel Plates ◽  
Finishing Processes ◽  
Compressive Residual Stresses

This investigation examines the effects of different finishing processes on the fatigue life of premachined holes in Assab 760 steel plates. The finishing processes studied were reaming, ballizing, and emery polishing. A general decrease in fatigue life with increase in surface roughness is observed for all the processes employed. In comparing the different processes, for a constant surface roughness, polishing is generally found to give the longest fatigue life while ballizing, in spite of the greater compressive residual stresses induced on the surface of the finished hole, the shortest. The surprising phenomenon was found to be attributed to the amount of plastic deformation occurred before fatigue loading. For Assab 760 steel, a prestrain in the radial direction of less than about 2.5 percent appeared to reduce the fatigue resistance of the material.

Finite Element Analysis of Residual Stresses in Threaded End Closures

1991 ◽  
Vol 113 (3) ◽  
pp. 398-401 ◽  
Author(s):  
A. Chaaban ◽  
U. Muzzo
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Bauschinger Effect ◽  
High Stress ◽  
Empirical Method ◽  
Pressure Vessels ◽  
Element Analysis ◽  
High Stress Concentration ◽  
Proof Testing ◽  
Pressure Cycle

Due to the high stress concentration at the root of the first active thread in threaded end closures of high pressure vessels, yielding may occur in this region during the application of the first pressure cycle or proof testing. This overstraining introduces residual stresses that influence the fatigue performance of the vessel. This paper presents a parametric analysis of threaded end closures using elastic and elasto-plastic finite element solutions. The results are used to discuss the influence of these residuals on the estimated fatigue life when the vessel is subjected to repeated internal pressure. A simple empirical method to allow for the Bauschinger effect of the material is also proposed.

Solidification Heat Transfer and Base Separation Analysis in the Casting of an Energetic Material in a Projectile

2005 ◽  
Author(s):  
Dawei Sun ◽  
S. Ravi Annapragada ◽  
Suresh V. Garimella ◽  
Sanjeev Sing
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Numerical Model ◽  
Residual Stresses ◽  
Energetic Materials ◽  
Energetic Material ◽  
Complex Geometries ◽  
Experimental Measurements ◽  
Linear Temperature ◽  
High Prandtl Number

This paper investigates the problem of base separation in the casting of energetic materials in a projectile. Special challenges that arise in casting high Prandtl number energetic materials in projectiles of complex geometries are addressed. A comprehensive numerical model is developed by integrating finite volume and finite element methods to analyze the thermal and flow fields as well as the residual stresses. The predictions, which are confirmed by experimental measurements, suggest that sustenance of a linear temperature profile along the projectile axis can eliminate base separation, and also reduce residual stresses in the final casting.

Finite Element Analysis of the Effect of Twist on Chain Fatigue Performance

2019 ◽  
Author(s):  
Justin Jones
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Stress State ◽  
Element Analysis ◽  
Contact Patch ◽  
Multiaxial Stress State ◽  
Twisted State ◽  
Residual Stress State ◽  
Proof Testing

Abstract Mooring chains may be installed with twist or become twisted during service. This paper describes an investigation of the effect of a range of twist angles on the fatigue life of studless chain through the use of detailed finite element analysis. The analysis includes the local contact patch deformation and residual stress state that results from plasticity during the proof testing of the chain. The effect of high in-service tension resulting from storms that produces additional plasticity when the chain is loaded in the twisted state is also included. The change in fatigue life at the crown, inner bend and around the contact patch are assessed. Local to the contact patch the fatigue life calculation includes an assessment of the multiaxial stress state. For small angles of twist the calculated fatigue life at the crown and around the contact increases and that at the inner bend sees a marginal reduction. At twist angles above 12 to 14 degrees per link the calculated inner bend and contact patch fatigue lives reduce markedly with increasing twist, but the crown fatigue life continues to increase.

Stress and Strain Analysis of Composite Gas Cylinder Based on ABAQUS

2012 ◽  
Vol 557-559 ◽  
pp. 300-303
Author(s):  
Cheng Hong Duan ◽  
Xiang Peng Luo ◽  
Nan Zhang
Keyword(s):  
Finite Element ◽  
Strain Analysis ◽  
Element Model ◽  
Stress And Strain ◽  
Analysis Method ◽  
Element Analysis ◽  
Finite Element Software ◽  
Finite Element Analysis Method ◽  
Gas Cylinder ◽  
Gas Cylinders

In this paper, a finite element model of a composite gas cylinder was established by ABAQUS finite element software, with consideration that both heads were helically wound and their wound angle and wound thickness varied with different parallel circle radius. Stress of the composite gas cylinder and PEEQ of its liner under different working conditions after autofrettage treatment were studied, the stress distribution was assessed by the DOT CFFC standard and the effective range of autofrettage treatment was confirmed. This finite element analysis method may be referable to the design and inspection of composite gas cylinders.

Elastic-Plastic Finite Element Analysis of Nonsteady State Partial Slip Wheel-Rail Rolling Contact

2005 ◽  
Vol 127 (4) ◽  
pp. 713-721 ◽  
Author(s):  
Zefeng Wen ◽  
Xuesong Jin ◽  
Yanyao Jiang
Keyword(s):  
Finite Element Analysis ◽  
Plastic Deformation ◽  
Finite Element ◽  
Residual Stresses ◽  
Contact Force ◽  
Rolling Contact ◽  
Element Analysis ◽  
Normal Contact ◽  
Nonsteady State ◽  
Residual Stresses And Strains

A finite element analysis with the implementation of an advanced cyclic plasticity theory was conducted to study the elastic-plastic deformation under the nonsteady state rolling contact between a wheel and a rail. The consideration of nonsteady state rolling contact was restricted to a harmonic variation of the wheel-rail normal contact force. The normal contact pressure was idealized as the Hertzian distribution, and the tangential force presented by Carter was used. Detailed rolling contact stresses and strains were obtained for repeated rolling contact. The harmonic variation of the normal (vertical) contact force results in a wavy rolling contact surface profile. The results can help understand the influence of plastic deformation on the rail corrugation initiation and growth. The creepage or stick-slip condition greatly influences the residual stresses and strains. While the residual strains and surface displacements increased at a reduced rate with increasing rolling passes, the residual stresses stabilize after a limited number of rolling passes. The residual stresses and strains near the wave trough of the residual wavy deformation are higher than those near the wave crest.

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