The Single Slice Method for Measurement of Axisymmetric Residual Stresses in Solid Rods or Hollow Cylinders in the Region of Plane Strain

1998 ◽  
Vol 120 (2) ◽  
pp. 170-176 ◽  
Author(s):  
Weili Cheng ◽  
lain Finnie
Keyword(s):  
Residual Stresses ◽  
Plane Strain ◽  
Experimental Approach ◽  
Axial Stress ◽  
Strain Gages ◽  
Experimental Procedure ◽  
Thin Slice ◽  
Hollow Cylinders ◽  
Slice Method ◽  
Hoop Stresses

A new method is presented for the measurement of axisymmetric residual stresses in a solid rod or hollow cylinder in the region which is in a state of plane strain. The experimental procedure involves, first, making a complete transverse cut, normal to the axis of the part in the region which is initially in plane strain. Next, a number of strain gages are mounted on one of the faces produced by the first cut. A second transverse cut, parallel to the first, is then made to remove a thin slice containing the strain gages. It is shown that the change in strain gage readings due to removal of the slice may be used to deduce the axial stress in plane strain at the location of the first cut. The hoop stresses in the thin slice, which is in a state of plane stress, are readily obtained from the “crack compliance” procedure which we have described in earlier work. From this information and the initial axial stress in plane strain it is shown that the initial hoop and radial stresses in plane strain may be determined. The method is validated by obtaining the stresses in a water quenched rod which are shown to be in excellent agreement with those measured using a different experimental approach. Since the method does not require the measurement to be carried out on the original rod or cylinder, it allows the original residual stresses to be measured from a fractured shaft by making a slice near the plane of the fracture if the fracture is dominated by elastic deformation.

Estimation of Axisymmetric Residual Stresses in a Long Cylinder

1992 ◽  
Vol 114 (2) ◽  
pp. 137-140 ◽  
Author(s):  
W. Cheng ◽  
I. Finnie ◽  
O¨. Vardar
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Plane Strain ◽  
Plane Stress ◽  
Stress Measurement ◽  
Residual Stress Measurement ◽  
Experimental Procedure ◽  
Linear Elastic ◽  
Hoop Stresses ◽  
Long Cylinder

An approach based on linear elastic equations is developed to predict axisymmetric axial and radial residual stresses in a long cylinder in plane strain from hoop stresses measured in both plane strain and plane stress. This approach, when combined with the authors’ crack compliance method for residual stress measurement, leads to a simplified experimental procedure for measurement of axisymmetric residual stresses in cylinders.

Wheel Rim Axial Residual Stress and a Proposed Mechanism for Vertical Split Rim Formation

2011 ◽  
Author(s):  
Cameron Lonsdale ◽  
John Oliver
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Axial Stress ◽  
X Ray Diffraction ◽  
X Ray ◽  
Axial Residual Stress ◽  
Railroad Wheels ◽  
Hoop Stresses ◽  
Future Work

Railroad wheels are manufactured with beneficial residual compressive hoop stresses, which are imparted by rim quenching and tempering. Hoop and radial residual stresses for wheels have been studied in detail by various organizations over the years and are relatively well characterized. However axial residual stresses, in the orientation across the rim width from back rim face to front rim face, have not been extensively investigated. This paper describes a failure mode known as a vertical split rim (VSR) and describes efforts to measure the axial residual stresses in, 1) new wheels, 2) service worn wheels and 3) wheels that have failed from VSRs. Initial axial residual stress measurement efforts, using core drilling and x-ray diffraction from the tread surface, are briefly reviewed. Further more extensive work using x-ray diffraction to measure axial residual stress on radial wheel slices is described and data are presented, focusing on differences between the three wheel types. The concept of Axial Stress Amplification (ASA) is outlined, and the relationship of axial residual stress to VSRs is discussed. A proposed mechanism for VSR formation is described. Future work, with a goal of reducing or eliminating VSRs in service, is considered.

A Critical Examination of Sachs’ Material-Removal Method for Determination of Residual Stress

2003 ◽  
Author(s):  
Anthony P. Parker
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Critical Examination ◽  
Fatigue Lifetime ◽  
Experimental Procedure ◽  
Linear Elastic ◽  
Order Of Magnitude ◽  
Hoop Stresses ◽  
Elastic Unloading

Sachs’ method is an experimental procedure used primarily in the determination of residual stresses in autofrettaged thick cylinders. In its usual form it involves fixing axial and hoop direction strain gauges to the OD of a tube; strain readings are then obtained after each incremental removal of material from the bore. Sachs’ analysis assumes that the remaining tube unloads in linear-elastic fashion throughout the process and that superposition may therefore be employed to quantify the residual stresses within the original tube. By numerical simulation of two complete Sachs’ experimental sequences with ‘open end’ conditions it is demonstrated that the assumption of elastic unloading is invalidated by the Bauschinger effect. Sachs’ method thereby overestimates compressive residual bore hoop stresses in a typical tube by between 24% and 43%. If used as the basis for cyclic pressurization fatigue lifetime predictions with pre-existing cracks, such discrepancies will cause overestimates in fatigue lifetime of an order of magnitude. Sachs’ experimental procedure is therefore not recommended as a reliable or conservative method for determination of residual stress.

Effects of Initial Tube-Tubesheet Clearance and Grooves on Axial and Hoop Residual Stresses of Roller Expanded Joints

2010 ◽  
Author(s):  
A. N. Shuaib ◽  
O. M. Duffuaa ◽  
N. Merah ◽  
Y. Al-Nassar
Keyword(s):  
Residual Stresses ◽  
Hoop Stress ◽  
Axial Stress ◽  
Element Model ◽  
Radial Clearance ◽  
Radial Deformation ◽  
Initiation And Propagation ◽  
Hoop Stresses ◽  
Corrosive Environments ◽  
Degrees Of Severity

An axisymmetric finite element model is used to evaluate the effect of large initial tube-tubesheet radial clearance and the effect of grooves machined in the tubesheet hole on the distributions and magnitudes of the radial deformation of expanded tube walls, residual contact stress, residual hoop stress, and residual axial stress along the expanded length of the tube and in the transition zone. The results have revealed the presence of residual axial stresses and residual hoop stresses in the inside and outside surfaces of the tubes with various degrees of severity. These tensile residual stresses may cause crack initiation and propagation and may lead stress corrosion cracking in corrosive environments.

A Critical Examination of Sachs’ Material-Removal Method for Determination of Residual Stress

2004 ◽  
Vol 126 (2) ◽  
pp. 234-236 ◽  
Author(s):  
Anthony P. Parker
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Critical Examination ◽  
Fatigue Lifetime ◽  
Experimental Procedure ◽  
Linear Elastic ◽  
Order Of Magnitude ◽  
Hoop Stresses ◽  
Elastic Unloading

Sachs’ method is an experimental procedure used primarily in the determination of residual stresses in autofrettaged thick cylinders. In its usual form it involves fixing axial and hoop direction strain gauges to the OD of a tube; strain readings are then obtained after each incremental removal of material from the bore. Sachs’ analysis assumes that the remaining tube unloads in linear-elastic fashion throughout the process and that superposition may therefore be employed to quantify the residual stresses within the original tube. By numerical simulation of two complete Sachs’ experimental sequences with “open end” conditions it is demonstrated that the assumption of elastic unloading is invalidated by the Bauschinger effect. Sachs’ method thereby overestimates compressive residual bore hoop stresses in a typical tube by between 24% and 43%. If used as the basis for cyclic pressurization fatigue lifetime predictions with pre-existing cracks, such discrepancies will cause overestimates in fatigue lifetime of an order of magnitude. Sachs’ experimental procedure is therefore not recommended as a reliable or conservative method for determination of residual stress.

Relaxation of Residual Stresses in and around Mechanical Fasteners Due to Fatigue Loading

2006 ◽  
Vol 524-525 ◽  
pp. 153-158 ◽  
Author(s):  
Matthew E. Fox ◽  
Philip J. Withers
Keyword(s):  
Residual Stresses ◽  
Hoop Stress ◽  
Fatigue Cracks ◽  
Fatigue Loading ◽  
Far Field ◽  
Synchrotron Diffraction ◽  
Fastener Hole ◽  
Single Plate ◽  
Mechanical Fasteners ◽  
Hoop Stresses

The residual stresses around clearance-fit mechanical fasteners have been found to be similar to those around cold expanded holes where compressive hoop stresses close to the fastener hole are balanced by far-field tensile stresses. This compressive zone has been shown to prolong fatigue lifetimes around fastener holes. Constant amplitude fatigue loading was applied to single plate rivet specimens for varying numbers of cycles to investigate the redistribution of these stresses after fatiguing. Synchrotron diffraction was used to map the evolution of the residual stresses around the rivets. Little change in the hoop stress local to the rivets occurred until visible fatigue cracks were observed suggesting that relaxation of these stresses is due to the cracks rather than their cause.

Investigation of Residual Stress/Strain and Texture in a Large Dissimilar Metal Weld Using Synchrotron Radiation and Neutrons

2013 ◽  
Vol 772 ◽  
pp. 193-199 ◽  
Author(s):  
Carsten Ohms ◽  
Rene V. Martins
Keyword(s):  
Synchrotron Radiation ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Large Scale ◽  
High Energy ◽  
X Ray Diffraction ◽  
Butt Weld ◽  
X Ray ◽  
Component Size ◽  
Thin Slice

Bi-metallic piping welds are frequently used in light water nuclear reactors to connect ferritic steel pressure vessel nozzles to austenitic stainless steel primary cooling piping systems. An important aspect for the integrity of such welds is the presence of residual stresses. Measurement of these residual stresses presents a considerable challenge because of the component size and because of the material heterogeneity in the weld regions. The specimen investigated here was a thin slice cut from a full-scale bi-metallic piping weld mock-up. A similar mock-up had previously been investigated by neutron diffraction within a European research project called ADIMEW. However, at that time, due to the wall thickness of the pipe, stress and spatial resolution of the measurements were severely restricted. One aim of the present investigations by high energy synchrotron radiation and neutrons used on this thin slice was to determine whether such measurements would render a valid representation of the axial strains and stresses in the uncut large-scale structure. The advantage of the small specimen was, apart from the easier manipulation, the fact that measurement times facilitated a high density of measurements across large parts of the test piece in a reasonable time. Furthermore, the recording of complete diffraction patterns within the accessible diffraction angle range by synchrotron X-ray diffraction permitted mapping the texture variations. The strain and stress results obtained are presented and compared for the neutron and synchrotron X-ray diffraction measurements. A strong variation of the texture pole orientations is observed in the weld regions which could be attributed to individual weld torch passes. The effect of specimen rocking on the scatter of the diffraction data in the butt weld region is assessed during the neutron diffraction measurements.

Investigation of the Biaxial Behaviour of 316 Stainless Steel Based on Critical Plane Method

2018 ◽  
Vol 774 ◽  
pp. 510-515
Author(s):  
A.S. Cruces ◽  
Pablo Lopez-Crespo ◽  
Belen Moreno ◽  
S. Bressan ◽  
Takamoto Itoh
Keyword(s):  
Stainless Steel ◽  
Hoop Stress ◽  
Axial Stress ◽  
Critical Plane ◽  
316 Stainless Steel ◽  
Dog Bone ◽  
Critical Plane Approach ◽  
Hoop Stresses ◽  
Life Predictions ◽  
Biaxial Behavior

In this work the biaxial behavior of 316 stainless steel is studied under the lens of critical plane approach. A series of ten experiments were developed on dog bone shape hollow cylindrical specimens made of type 316 stainless steel. Five different loading conditions were assessed, with (i) only axial stress, (ii) only hoop stress, (iii) proportional combination of axial and hoop stresses, (iv) non-proportional combination of axial and hoop stresses with square shape and (v) non-proportional combination of axial and hoop stresses with L-shape. The fatigue analysis is performed following four different critical plane theories, namely Wang-Brown, Fatemi-Socie, Liu I and Liu II. The efficiency of all four theories is studied in terms of the accuracy of their life predictions.

Determination of the Residual Stresses in Composite Laminate Using the Compliance Method

2005 ◽  
Vol 490-491 ◽  
pp. 533-538 ◽  
Author(s):  
Guillaume Montay ◽  
Olivier Sicot ◽  
X.L. Gong ◽  
Abel Cherouat ◽  
Jian Lu
Keyword(s):  
Experimental Data ◽  
Residual Stresses ◽  
Composite Laminates ◽  
Composite Laminate ◽  
Constant Width ◽  
Strain Gages ◽  
New Methods ◽  
Structure Surface ◽  
Finite Elements Simulation

Residual stresses play an important role on the mechanical behavior of composite laminate. The development of new methods to determine the residual stresses gradient within the laminates is necessary. This article presents the adaptation of the compliance method in the case of composite laminates carbon/epoxy [02/902]s. The incremental drilling of a constant width groove allows for each increment to measure the strains (using strain gages) and displacements (using an optical device) of particularly points of the structure surface. These experimental data are compared with results given by a finite elements simulation. This comparison allows to raise the residual stresses in the composite laminate.

X-ray residual stress analysis of cylindrically curved surfaces—estimation of circumferential distributions of residual stresses

2003 ◽  
Vol 38 (5) ◽  
pp. 459-468 ◽  
Author(s):  
T Oguri ◽  
K Murata ◽  
Y Sato
Keyword(s):  
Residual Stresses ◽  
Least Squares Method ◽  
Stress Measurement ◽  
Incident Angle ◽  
Axial Stress ◽  
Circumferential Stress ◽  
Distribution Functions ◽  
Scanning Method ◽  
X Ray ◽  
Reference Axis

A new measuring technique utilizing X-ray diffraction is proposed in order to estimate the circumferential distributions of residual stresses on convex/concave cylindrical surfaces. This technique requires neither tilting X-ray beams in the circumferential direction in which the X-ray incident angle tends to be limited nor adjusting the normal of the irradiation area to the reference axis of the ψ angle. The circumferential distributions of the circumferential stress and of the axial stress are estimated from the diffraction angles at ψ = 0° and the axial stresses obtained by the stress measurement on multiple inclined areas on the cylindrical surfaces under the configuration of the axial stress measurement using the iso-inclination scanning method. This estimate technique was applied to two round bars of steel, one with circumferential distributions of the residual stresses and the other with almost uniform stresses. The distribution functions of the residual stresses were expanded to a couple of Fourier series, and the coefficients of them were determined by the least-squares method. The estimated distributions of the residual stresses were in good agreement with the actual ones.

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