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.

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%.

Experimental Investigation on Residual Stress of Model S1100 of Crankshaft Chamfer Based on XRD

2007 ◽  
Vol 353-358 ◽  
pp. 2301-2304
Author(s):  
Yong Kang Zhang ◽  
De Jun Kong ◽  
Jin Zhon Lu ◽  
Ai Xin Feng ◽  
Xu Dong Ren ◽  
...  
Keyword(s):  
Residual Stress ◽  
Experimental Investigation ◽  
Fatigue Life ◽  
Stress Distribution ◽  
Service Life ◽  
Residual Stresses ◽  
Fatigue Testing ◽  
Residual Stress Distribution ◽  
Isothermal Quenching ◽  
Main Factors

Residual stresses of model S1100 of crankshaft chamfer were measured by the technology of XRD. The distributions of residual stresses under mechanical peening, mechanical rolling and isothermal quenching are measured, and the tests of fatigue life were conducted. The results showed that the distribution of residual stress by machining in the crankshaft chamfer is complicated, which is at the tensile-compressive status, and it is one of the main factors to affect fatigue life of the crankshaft; isothermal quenching improves the distribution of residual stress, and tensile stress of the crankshaft chamfer is changed into the compressive stress, which may satisfy the requests of fatigue testing for 5 × 106 cycles. Although the mechanical rolling improved the residual stress distribution in the chamfer linked with the crank, tensile stresses in the chamfer connected with the linkage also increase, which influences the service life of the crankshaft.

Effect of Heat Treatment Conditions and Densities on Residual Stresses at Hybrid (FLN2-4405) P/M Steels

2007 ◽  
Vol 534-536 ◽  
pp. 669-672 ◽  
Author(s):  
Fırat Kafkas ◽  
Çetin Karatas ◽  
Suleyman Saritaş
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Maximum Level ◽  
Residual Stress Distribution ◽  
Minimum Level ◽  
Treatment Conditions ◽  
Removal Technique ◽  
Hardened Condition

The characteristics of residual stresses occurring in PM steel based nickel (FLN2-4405) was investigated. Residual stresses were measured by electrochemical layer removal technique. The values and distributions of residual stresses occurring in PM steel processed under various densities (6.8, 7.05, 7.2 and 7.4 g/cm3) and heat treatment conditions (sintered at 2050 ºF, sintered at 2300 ºF, quenching-tempered, and sinter-hardened) were determined. In most of the experiments, tensile residual stresses were recorded on the surface of the samples. The residual stress distribution on the surface of the PM steels was found to be affected by the heat treatment conditions and density. The maximum values of residual stresses on the surface showed sinter hardened condition and a density of 7.4 g/cm3. The minimum level of recorded tensile residual stresses are150 MPa and its maximum level is 370 MPa.

Effects of Heat-Treatment Residual Stress on Low Cycle Fatigue Life of a Turbine Disk in PM Superalloy

2015 ◽  
Author(s):  
Rongqiao Wang ◽  
Da Li ◽  
Dianyin Hu ◽  
Yang Hai ◽  
Jun Song
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Low Cycle Fatigue ◽  
Turbine Disk ◽  
Cycle Fatigue ◽  
Residual Stress Field ◽  
Turbine Disks ◽  
Pm Superalloy

Turbine disks in powder metallurgy (PM) superalloy have been widely used in advanced aeroengines. The production of PM superalloy turbine disks involves a series of heat treatment processes, which would inevitably create residual stresses. It has been proved that the low cycle fatigue (LCF) life of the turbine disk is affected by the residual stresses. The computational simulation of heat treatment is considered as an effective way to evaluate the residual stresses in a turbine disk. A finite element software was used to simulate the heat-treatment processes of a FGH95 turbine disk to obtain the residual stress field. To investigate the relaxation of residual stress in FGH95, smooth bar specimens were measured by X-ray diffraction before and after being loaded. Modified by the residual stresses, SWT model is used to predict the low cycle fatigue life of the turbine disk modified by the residual stress field obtained from the simulation of heat treatment. By the comparison between the prediction modified by the residual stress and the prediction without modification, a considerable decrease in low cycle fatigue life is indicated.

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 Stress Distribution in Feal Weld Overlay on Steel

1994 ◽  
Vol 364 ◽  
Author(s):  
X.-L. Wang ◽  
S. Spooner ◽  
C. R. Hubbard ◽  
P. J. Maziasz ◽  
G. M. Goodwin ◽  
...  
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Post Weld Heat Treatment ◽  
Residual Stress Distribution ◽  
Element Analysis ◽  
Weld Overlay

AbstractNeutron diffraction was used to measure the residual stress distribution in an FeAl weld overlay on steel. It was found that the residual stresses accumulated during welding were essentially removed by the post-weld heat treatment that was applied to the specimen; most residual stresses in the specimen developed during cooling following the post-weld heat treatment. The experimental data were compared with a plasto-elastic finite element analysis. While some disagreement exists in absolute strain values, there is satisfactory agreement in strain spatial distribution between the experimental data and the finite element analysis.

Theoretical prediction of residual stresses induced by cold spray with experimental validation

2019 ◽  
Vol 15 (3) ◽  
pp. 599-616 ◽  
Author(s):  
Dibakor Boruah ◽  
Xiang Zhang ◽  
Matthew Doré
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Cold Spray ◽  
Residual Stress Distribution ◽  
Thermal Mismatch ◽  
Individual Layer ◽  
Content Type ◽  
Layer Height ◽  
Proposed Model

PurposeThe purpose of this paper is to develop a simple analytical model for predicting the through-thickness distribution of residual stresses in a cold spray (CS) deposit-substrate assembly.Design/methodology/approachLayer-by-layer build-up of residual stresses induced by both the peening dominant and thermal mismatch dominant CS processes, taking into account the force and moment equilibrium requirements. The proposed model has been validated with the neutron diffraction measurements, taken from the published literature for different combinations of deposit-substrate assemblies comprising Cu, Mg, Ti, Al and Al alloys.FindingsThrough a parametric study, the influence of geometrical variables (number of layers, substrate height and individual layer height) on the through-thickness residual stress distribution and magnitude are elucidated. Both the number of deposited layers and substrate height affect residual stress magnitude, whereas the individual layer height has little effect. A good agreement has been achieved between the experimentally measured stress distributions and predictions by the proposed model.Originality/valueThe proposed model provides a more thorough explanation of residual stress development mechanisms by the CS process along with mathematical representation. Comparing to existing analytical and finite element methods, it provides a quicker estimation of the residual stress distribution and magnitude. This paper provides comparisons and contrast of the two different residual stress mechanisms: the peening dominant and the thermal mismatch dominant. The proposed model allows parametric studies of geometric variables, and can potentially contribute to CS process optimisation aiming at residual stress control.

A Further Study of Residual Stresses in Circumferential Welds

1973 ◽  
Vol 95 (4) ◽  
pp. 238-242 ◽  
Author(s):  
S. Vaidyanathan ◽  
H. Weiss ◽  
I. Finnie
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Base Metal ◽  
Filler Metal ◽  
Residual Stress Distribution ◽  
Experimental Results ◽  
Circumferential Welds ◽  
Single Pass ◽  
Full Penetration

The residual stress distribution for a circumferential weld between cylinders was obtained in a prior publication for a full penetration, single pass weld with no variation of alloy content across the weld. In the present work the approach is extended to cover a wider variety of weld conditions. It is shown that the effects of multipass welds, partial penetration welds, and welds with filler metal differing greatly in properties from the base metal can approximately be taken into account. Experimental results are presented to support the proposed method of analysis.

scholarly journals Separation of the Formation Mechanisms of Residual Stresses in LPBF 316L

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1234
Author(s):  
Alexander Ulbricht ◽  
Simon J. Altenburg ◽  
Maximilian Sprengel ◽  
Konstantin Sommer ◽  
Gunther Mohr ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Residual Stress Distribution ◽  
Formation Mechanisms ◽  
Micro Computed Tomography ◽  
Solidification Shrinkage ◽  
Stainless Steel 316L ◽  
Heat Accumulation ◽  
Cooling Rates

Rapid cooling rates and steep temperature gradients are characteristic of additively manufactured parts and important factors for the residual stress formation. This study examined the influence of heat accumulation on the distribution of residual stress in two prisms produced by Laser Powder Bed Fusion (LPBF) of austenitic stainless steel 316L. The layers of the prisms were exposed using two different border fill scan strategies: one scanned from the centre to the perimeter and the other from the perimeter to the centre. The goal was to reveal the effect of different heat inputs on samples featuring the same solidification shrinkage. Residual stress was characterised in one plane perpendicular to the building direction at the mid height using Neutron and Lab X-ray diffraction. Thermography data obtained during the build process were analysed in order to correlate the cooling rates and apparent surface temperatures with the residual stress results. Optical microscopy and micro computed tomography were used to correlate defect populations with the residual stress distribution. The two scanning strategies led to residual stress distributions that were typical for additively manufactured components: compressive stresses in the bulk and tensile stresses at the surface. However, due to the different heat accumulation, the maximum residual stress levels differed. We concluded that solidification shrinkage plays a major role in determining the shape of the residual stress distribution, while the temperature gradient mechanism appears to determine the magnitude of peak residual stresses.

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