Modelling and experimental characterisation of a residual stress field in a ferritic compact tension specimen

2009 ◽  
Vol 86 (12) ◽  
pp. 830-837 ◽  
Author(s):  
M.R. Wenman ◽  
A.J. Price ◽  
A. Steuwer ◽  
P.R. Chard-Tuckey ◽  
A. Crocombe
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Tension Specimen ◽  
Residual Stress Field ◽  
Experimental Characterisation

Measurements of Residual Stress in a Welded Compact Tension Specimen Using the Neutron Diffraction and Slitting Techniques

2010 ◽  
Vol 652 ◽  
pp. 210-215 ◽  
Author(s):  
Foroogh Hosseinzadeh ◽  
P. John Bouchard ◽  
Jonathan A. James
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Significant Contribution ◽  
Creep Crack Growth ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Tension Specimen ◽  
Residual Stress Field ◽  
Butt Weld ◽  
Crack Driving Force

The residual stress field in a compact tension specimen blank extracted from a non-stress-relieved thick section butt weld has been measured using neutron diffraction and the slitting method. Significant triaxial residual stresses were found in the specimen that is normally assumed to be stress free. Moreover the level of stress was sufficient to make a significant contribution to the crack driving force in creep crack growth tests. The benefits of using more than one measurement technique in such investigations are demonstrated.

Neutron Diffraction Measurement of the Stress Field During Fatigue Cycling of a Cracked Test Specimen

1989 ◽  
Vol 166 ◽  
Author(s):  
M.T. Hutchings ◽  
C.A. Hippsley ◽  
V. Rainey
Keyword(s):  
Fracture Mechanics ◽  
Neutron Diffraction ◽  
Stress Field ◽  
Test Specimen ◽  
Maximum Stress ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Diffraction Measurement ◽  
Tension Specimen ◽  
Neutron Diffraction Measurement

ABSTRACTThe triaxial stress field has been measured along the centre line of a compact tension specimen in the direction of cracking. The specimen had been subjected to ∼60,000 cycles at δK=31 and Kmax = 34 MPa mm½ and was bolted open at maximum stress. The field was remeasured after the stress had been fully relaxed. The results are discussed in terms of expectations from fracture mechanics calculations.

Study of Creep Relaxation Behaviour of 316H Austenitic Steels Under Mechanically Induced Residual Stress

2011 ◽  
Author(s):  
Hamed Yazdani Nezhad ◽  
Noel P. O’Dowd ◽  
Catrin M. Davies ◽  
Kamran M. Nikbin ◽  
Robert C. Wimpory
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Compact Tension ◽  
Load Level ◽  
Austenitic Steels ◽  
Combined Loading ◽  
Relaxation Behaviour ◽  
Residual Stress Field ◽  
Stress Profiles ◽  
Significant Distance

Compact tension 316H austenitic steel specimens, extracted from an as-received ex-service pressure vessel header, have been pre-compressed to different load levels in order to introduce a residual stress field. Finite element (FE) analysis has been performed to predict the load level required to obtain a high magnitude tensile stress field over a significant distance ahead of the notch while preventing a large plastic zone in the specimen. The predicted residual stress profiles along the crack path are compared with those measured using neutron diffraction (ND). Comparisons have also been provided between the ND results of this work with recent work carried out on 316H and 347 stainless steels under different loading levels. The creep relaxation behaviour of the steel has been studied numerically. A proposed method to estimate the steady state creep crack tip parameter, C*, has been examined using the obtained displacement rates for the case of combined loading. Creep relaxation data for combined stresses are compared with the earlier studies.

Measurement of the residual stress field in MIG-welded Al-2024 and Al-7150 aluminium alloy compact tension specimens

2006 ◽  
Vol 437 (1) ◽  
pp. 46-53 ◽  
Author(s):  
S. Pratihar ◽  
V. Stelmukh ◽  
M.T. Hutchings ◽  
M.E. Fitzpatrick ◽  
U. Stuhr ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Aluminium Alloy ◽  
Compact Tension ◽  
Residual Stress Field ◽  
Al 2024

An evaluation of residual stress distribution in welded compact tension specimens using neutron diffraction

2005 ◽  
Vol 40 (2) ◽  
pp. 211-216 ◽  
Author(s):  
G. O Rading
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Neutron Diffraction ◽  
Stress Field ◽  
Fatigue Cracks ◽  
Compact Tension ◽  
Maximum Tensile Stress ◽  
Thickness Variation ◽  
Residual Stress Field ◽  
Neutron Diffraction Technique

The neutron diffraction technique was used to determine the residual stress field in welded compact tension specimens of the aluminium-lithium alloy AA 2095. The deep penetrating characteristic of neutrons was exploited to evaluate the through-thickness variation in residual stress. Moreover, insight into the redistribution of these stresses was gained by extending a fatigue crack through the residual stress field and re-examining the stress distribution. The specimen without a crack was found to have a high compressive stress (of the order of - 135MPa) ahead of the notch. This rose to a maximum tensile stress of about 50MPa, 22 mm from the notch, followed by a drop to negative values further ahead of the notch. It was observed that the magnitude of the stresses changed on moving into the thickness of the specimen. However, the form of the graph showing stress versus distance ahead of the notch remained unchanged. When fatigue cracks of different lengths were introduced, the magnitude of the stress close to the tip first increased with crack length, before decreasing and then rising again. Nevertheless, the form of the graph remained unchanged and the stress at the crack tip remained compressive. The paper concludes that any study of the response of a component to mechanical loading involving a residual stress field must take these factors (i.e. through-thickness stress variation and stress redistribution) into consideration.

Measurements of Residual Stresses in 316 Stainless Steel Weldments

2010 ◽  
Author(s):  
C. M. Davies ◽  
D. Hughes ◽  
R. C. Wimpory ◽  
David W. Dean ◽  
K. M. Nikbin
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Crack Growth ◽  
Creep Crack Growth ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Stress Distributions ◽  
Tension Specimen ◽  
Creep Crack ◽  
Term Creep

Neutron diffraction measurements have been performed to quantify the residual stresses distributions in austenitic type 316 stainless steel Manual Metal Arc (MMA) weldment sections, which are similar to those used in creep crack growth testing. Measurements have been taken along the expected crack path in these samples to determine the influence of residual stresses on high temperature crack growth. The influence of EB welding extension pieces onto the weldments sections, in order to increase specimen size, and sample cutting for compact tension specimen manufacture are also examined. Similar stress distributions have been measured in nominally identical MMA weldments sections, where peak stresses of up to 120 MPa have been shown. The effects of the EB weld used to attach extension pieces to the weldments sections dominate over the MMA weldments residual stress distributions in these samples, and increases the peak stresses by up to a factor of three. Significant stress relaxation takes place during compact tension specimen manufacture, and in addition creep strain accumulation will further relax these residual stresses. Residual stress effects are therefore considered to only influence the creep crack initiation period in short-term creep crack growth tests. However, in long-term creep crack growth tests, the residual stresses may also influence subsequent creep crack growth behaviour.

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