Abrasive Waterjet Peening With Elastic Prestress: Subsurface Residual Stress Distribution

2007 ◽  
Author(s):  
Balaji Sadasivam ◽  
Alpay Hizal ◽  
Dwayne Arola
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Stress Field ◽  
Yield Strength ◽  
Residual Stresses ◽  
Residual Stress Distribution ◽  
Abrasive Waterjet ◽  
Residual Stress Field ◽  
Surface Residual Stress ◽  
Compressive Residual Stresses

Recent advances in abrasive waterjet (AWJ) technology have resulted in new processes for surface treatment that are capable of introducing compressive residual stresses with simultaneous changes in the surface texture. While the surface residual stress resulting from AWJ peening has been examined, the subsurface residual stress field resulting from this process has not been evaluated. In the present investigation, the subsurface residual stress distribution resulting from AWJ peening of Ti6Al4V and ASTM A228 steel were studied. Treatments were conducted with the targets subjected to an elastic prestress ranging from 0 to 75% of the substrate yield strength. The surface residual stress ranged from 680 to 1487 MPa for Ti6Al4V and 720 to 1554 MPa for ASTM A228 steel; the depth ranged from 265 to 370 μm for Ti6Al4V and 550 to 680 μm for ASTM A228 steel. Results showed that elastic prestress may be used to increase the surface residual stress in AWJ peened components by up to 100%.

Neutron Diffraction Studies of Residual Stresses Around Gouges and Gouged Dents

2012 ◽  
Author(s):  
Lynann Clapham ◽  
Vijay Babbar ◽  
Thomas Gnaeupel-Herold ◽  
Remi Batisse ◽  
Mures Zarea
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Neutron Diffraction ◽  
Stress Field ◽  
Residual Stresses ◽  
Wall Stress ◽  
Outer Wall ◽  
Stress Distributions ◽  
Wall Surface ◽  
Residual Stress Field

The residual stress pattern surrounding gouges is complex and, to date, has not been accurately modeled using stress modeling software. Thus measurement of these stress distributions is necessary. Neutron diffraction is the only experimental method with the capability of directly evaluating residual strain throughout the entire thickness of a pipe wall, in and around dent or gouged regions. Neutron diffraction measurements were conducted at the NIST reactor on three gouged dents in X52 pipeline sections. These were part of a larger sample set examined as part of the comprehensive MD4-1 PRCI/DOT PHMSA project. Gouges contained in pipeline sections were termed BEA161 (primarily a gouge with little denting), and BEA178 (mild gouging, very large dent). Measurements were also conducted on a coupon sample – P22, that was created as part of an earlier study. For the moderate gouges with little or no associated denting (BEA161 and P22) the residual stress field was highly localized around the immediate gouge vicinity (except where there was some denting present). The through wall stress distributions were similar at most locations — characterized by neutral or moderate hoop and axial stresses (50–100MPa) at the outer wall surface (i.e. at the gouge itself) gradually becoming highly compressive (up to −600MPa) at the inner wall surface. The other sample (BEA178) exhibited a very mild gouge with significant denting, and the results were very different. The denting process associated with this kind of gouge+dent dominated the residual stresses, making the residual stress distribution very complex. In addition, rather than having a residual stress field that is localized in the immediate gouge vicinity, the varying stress distribution extends to the edge of the dented region..

Prediction of Residual Stresses in Mooring Chains and its Impact on Fatigue Life

2017 ◽  
Author(s):  
Imanol Martinez Perez ◽  
Philippe Bastid ◽  
Vengatesan Venugopal
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Fatigue Life ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Sensitivity Study ◽  
Residual Stress Distribution ◽  
Residual Stress Field ◽  
Loading Mode ◽  
A Chain

This paper reports the results of a study conducted to investigate how residual stresses generated during the manufacturing process and subsequent proof loading may affect the fatigue life of mooring chains. The present paper shows the quantitative predictions of residual stress field obtained from finite element models of the fabrication process, and discusses their effect on the fatigue life of chain links depending on the loading mode. The models combine heat transfer analyses for the prediction of temperature histories during heat treatment (quenching and tempering), and stress analyses accounting for the thermo-mechanical history, including proof loading. The manufacturing conditions assumed for the models correspond to data obtained from a chain manufacturer. The predicted residual stress distribution is then combined with the fatigue stress range in service, due to either tension-tension loading or Out-of-Plane Bending (OPB). The effect of the residual stress distribution on the fatigue damage is discussed, and a sensitivity study on the assumptions used in the residual stress prediction is carried out. This determines for which loading conditions the modeling of the heat treatment stage can be neglected so that modeling of the proof loading step is sufficient for assessing the effect on fatigue life.

Modelling Fatigue Crack Growth in a Residual Stress Field

2006 ◽  
Author(s):  
A. J. Price ◽  
P. Tsakiropoulos ◽  
M. R. Wenman ◽  
P. R. Chard-Tuckey
Keyword(s):  
Fracture Toughness ◽  
Residual Stress ◽  
Fatigue Crack ◽  
Stress Distribution ◽  
Stress Field ◽  
Crack Growth ◽  
Nuclear Reactor ◽  
Element Model ◽  
Residual Stress Distribution ◽  
Residual Stress Field

Tensile residual stresses can have a detrimental affect on the safe operating limits of components. In most cases, these residual stress fields can be relieved through various treatments but in many cases it is not realistic to expect the complete elimination of these stresses. When considering the Reactor Pressure Vessel (RPV) located within a Nuclear Reactor Plant (NRP), knowledge of fatigue and fracture within a residual stress field is essential in support of safety cases. This research has investigated the behaviour of flaws that lie within a residual stress field with emphasis on fracture toughness through a series of fracture toughness tests. Alongside this experimental series, a finite element model has been created to predict the stress distributions prior to fracture. To enable an accurate simulation of the residual stress field distribution before loading to fracture it is important that the introduction of a fatigue crack is accurately modelled. This paper details several methods of introducing a fatigue crack into a simulation. During this research it has been shown that the introduction of a crack in progressive stages will lead to a better representation of the residual stress distribution prior to fracture. It has been shown that it is essential to use experimentally determined crack front shapes for the final stage of crack growth as this shape can significantly alter the residual stress distribution.

An Evaluation of Abrasive Waterjet Peening With Elastic Prestress

2009 ◽  
Vol 131 (1) ◽  
Author(s):  
B. Sadasivam ◽  
A. Hizal ◽  
S. Park ◽  
D. Arola
Keyword(s):  
Residual Stress ◽  
Yield Strength ◽  
Surface Texture ◽  
Surface Stress ◽  
Treatment Process ◽  
Abrasive Waterjet ◽  
Residual Stress Field ◽  
Surface Residual Stress ◽  
Stress Zone ◽  
Study Application

Abrasive waterjet peening (AWJP) has been conceived as a new surface treatment process capable of achieving desired changes in surface texture, chemistry, and residual stress simultaneously. In the present investigation, the influence of elastic prestress on the residual stress resulting from AWJP was studied. Treatments were conducted on steel, as well as nickel and titanium alloy targets subjected to an elastic prestress ranging from 0% to 75% of the material’s yield strength. The results showed that a tensile elastic prestress increases the surface residual stress and the depth of the compressive stress zone. The surface residual stress in each metal increased nonuniformly with magnitude of prestress; the maximum surface residual stress was obtained at an applied prestress between 45% and 60% of the substrate yield strength. Overall, the increases in surface stress and depth that were obtained reached 100% and 50%, respectively. There were no changes to the surface texture caused by the prestress. According to results of this study, application of an elastic prestress can serve as an effective method for improving characteristics of the residual stress field in components treated using AWJP.

scholarly journals Impact of the Process Parameters, the Measurement Conditions and the Pre-Machining on the Residual Stress State of Deep Rolled Specimens

2019 ◽  
Vol 3 (3) ◽  
pp. 56 ◽  
Author(s):  
Nataliya Lyubenova ◽  
Dirk Bähre ◽  
Lukas Krupp ◽  
Julie Fouquet ◽  
Titouan Cronier ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress State ◽  
Stress Field ◽  
Residual Stresses ◽  
Process Parameters ◽  
Polished Surface ◽  
Deep Rolling ◽  
Residual Stress Field ◽  
The Impact ◽  
Compressive Residual Stresses

Mechanical surface treatments, e.g., deep rolling, are widely spread finishing processes due to their ability to enhance the fatigue strength of the treated materials with means of cold working and inducement of favorable compressive residual stresses. Despite of the clear advantages of deep rolling, the controlled generation of compressive residual stresses is still a challenging task, as the process can be influenced by the pre-machining stress state of the treated material. Additionally, the exact characterization of the induced residual stress field is impacted by the specific characteristics of the applied measurement technique. Therefore, this paper is focused on the X-ray diffraction residual stress analysis of deep rolled specimens, pre-machined to achieve rough or polished surface. The deep rolling process was realized as a single-trace to avoid the influence of the other process parameters and the resulted residual stress field on the surface and in depth was investigated. Additionally, the surface residual stress profiles were determined using two different measuring devices to analyze the impact of the different measurement conditions.

Measurement and Prediction of the Residual Stress Field Generated by Side-Punching

2006 ◽  
Vol 128 (3) ◽  
pp. 451-459 ◽  
Author(s):  
A. H. Mahmoudi ◽  
D. Stefanescu ◽  
S. Hossain ◽  
C. E. Truman ◽  
D. J. Smith ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Residual Stresses ◽  
Measurement Techniques ◽  
Hole Drilling ◽  
X Ray Diffraction ◽  
Residual Stress Field ◽  
Surface Residual Stress ◽  
Alloy Plate ◽  
Near Surface

Side-punching is proposed as a method of introducing a well-defined residual stress field into a laboratory-sized test specimen. Such a specimen may subsequently be used to assess the influence of residual stresses on the fracture behavior of materials. Side-punching consists of simultaneously indenting opposite faces of a plate of material with rigid tools, using sufficient force to cause localized yielding over a finite-sized volume of material adjacent to the punching tools. This paper presents experimental measurements, obtained using three independent measurement techniques, of the residual stress field generated in an aluminium alloy plate after side-punching. Incremental center hole drilling is used to determine the near-surface residual stress field, while synchrotron x-ray diffraction and deep hole drilling are used to measure the through-thickness residual stress field along a path linking the two punch center points. Finite element (FE) predictions are also presented and compared to the measurements. There is very good agreement between all three sets of measurements and the FE results, which all show that the through-thickness residual stresses are compressive and attain a maximum value at the center of the plate. The results confirm the potential use of side-punching in residual stress-crack interaction studies.

The effect of high compressive loading on residual stresses and fatigue crack growth at cold expanded holes

2003 ◽  
Vol 38 (5) ◽  
pp. 419-427 ◽  
Author(s):  
D Stefanescu ◽  
M Dutta ◽  
D Q Wang ◽  
L Edwards ◽  
M. E Fitzpatrick
Keyword(s):  
Residual Stress ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Crack Growth ◽  
Compressive Loading ◽  
Residual Stress Distribution ◽  
Residual Stress Field ◽  
X Ray

The effect of monotonic compressive loading on the residual stresses developed at cold expanded fastener holes has been investigated using the neutron and X-ray diffraction techniques. Monotonic loading models the effect of the peak of a fatigue loading sequence experienced before a crack is initiated. It was found that the compressive loading significantly affected the residual stress distribution. A low load relaxed only the stresses near to the bore of the hole, whereas a larger load affected the stress distribution over a greater area. Residual stresses measured at the mandrel entrance face were more affected by the compressive loading than the residual stresses measured at the other segments of thickness. The comparison between the X-ray and neutron diffraction results showed that the techniques complemented each other well, enabling a three-dimensional residual stress distribution to be derived. This distribution was used for modelling the effect of compressive loading on fatigue crack growth, using a linear elastic fracture mechanics approach and assuming a stabilized residual stress field.

scholarly journals Residual stresses in thermite welded rails: significance of additional forging

2020 ◽  
Vol 64 (7) ◽  
pp. 1195-1212
Author(s):  
B. Lennart Josefson ◽  
R. Bisschop ◽  
M. Messaadi ◽  
J. Hantusch
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Residual Stresses ◽  
Weld Metal ◽  
Welding Process ◽  
Surface Zone ◽  
Fe Model ◽  
Uneven Surface ◽  
Residual Stress Field ◽  
High Dynamic

Abstract The aluminothermic welding (ATW) process is the most commonly used welding process for welding rails (track) in the field. The large amount of weld metal added in the ATW process may result in a wide uneven surface zone on the rail head, which may, in rare cases, lead to irregularities in wear and plastic deformation due to high dynamic wheel-rail forces as wheels pass. The present paper studies the introduction of additional forging to the ATW process, intended to reduce the width of the zone affected by the heat input, while not creating a more detrimental residual stress field. Simulations using a novel thermo-mechanical FE model of the ATW process show that addition of a forging pressure leads to a somewhat smaller width of the zone affected by heat. This is also found in a metallurgical examination, showing that this zone (weld metal and heat-affected zone) is fully pearlitic. Only marginal differences are found in the residual stress field when additional forging is applied. In both cases, large tensile residual stresses are found in the rail web at the weld. Additional forging may increase the risk of hot cracking due to an increase in plastic strains within the welded area.

Sign in / Sign up

Export Citation Format

Share Document