Mapping of Residual Stress Field Based on Residual-Stress-Free State by ESPI Analysis

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1534-1539 ◽  
Author(s):  
Dong Won Kim ◽  
Dongil Kwon
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Speckle Pattern ◽  
Free State ◽  
Electronic Speckle Pattern Interferometry ◽  
Residual Stress Field ◽  
Surface Residual Stress ◽  
Stress Mapping ◽  
Stress Free State ◽  
Film Substrate

We study the residual stress mapping of indented Cu by ESPI (electronic speckle pattern interferometry). Based on the identification of the residual stress-free state using electronic speckle pattern interferometry (ESPI), we modeled the relaxed stress in annealing, the thermal strdin/stress and the residual stress field in case of both single and film/substrate systems by using the thermo-elastic theory and the relationship between relaxed stresses and displacements. Thus we mapped the surface residual stress fields on the indented bulk Cu and the 0.5⊔ Au film by ESPI. In indented Cu, the normal and shear residual stress are distributed over -800 MPa to 700 MPa and -600 MPa to 600 MPa respectively around the indented point.

Mapping of Surface Residual Stress Field by Laser Interferometry Using Stress Relaxation Method

2002 ◽  
Vol 750 ◽  
Author(s):  
Dong-Won Kim ◽  
Nak-Kyu Lee ◽  
Kyung-Hoan Na ◽  
Dongil Kwon
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Speckle Pattern ◽  
Thermal Strain ◽  
Laser Interferometry ◽  
Relaxation Method ◽  
Electronic Speckle Pattern Interferometry ◽  
Residual Stress Field ◽  
Surface Residual Stress ◽  
Au Film

ABSTRACTBased on the identification of the residual stress-free state using electronic speckle pattern interferometry (ESPI), we modeled the relaxed stress in annealing, the thermal strain/stress and the residual stress field in case of both single and film/substrate systems by using the thermo-elastic theory and the relationship between relaxed stresses and displacements. Thus we mapped the surface residual stress fields on the indented bulk Cu and the 0.5μm Au film by ESPI. In indented Cu, the normal and shear residual stress are distributed over -800 MPa to 700 MPa and -600 MPa to 600 MPa respectively around the indented point and in deposited Au film on Si wafer, the tensile residual stress is uniformly distributed on the Au film from 500 MPa to 800 MPa. Also we measured the residual stress by the x-ray diffractometer (XRD) for the verification of above residual stress results by ESPI.

Determination of Residual-Stress-Free State and Mapping of Residual Stress Fields Using Speckle Interferometry and Thermal Relaxation

2003 ◽  
Vol 795 ◽  
Author(s):  
Dong-Won Kim ◽  
Jong-jin Kim ◽  
Dongil Son ◽  
Nak-Kyu Lee ◽  
Kyung-Hoan Na ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Speckle Pattern ◽  
Thermal Relaxation ◽  
Free State ◽  
Stress Fields ◽  
Lead Frame ◽  
Surface Residual Stress ◽  
Au Film ◽  
Stress Free State

ABSTRACTWe used an electronic speckle pattern interferometer (ESPI) for nondestructive measurement in-situ displacement fields in microsystems. A four-step phase-shift technique and magnifier with long working distance were adopted to increase displacement resolution to ∼10−2 μm and spatial resolution to ∼2 μm. A thermal vacuum chamber was designed to induce thermal treatments, including annealing. From the identification of the residual-stress-free state, we quantitatively modeled thermal strains/stress fields, relaxation stresses during annealing, and residual stress fields. Thermoelasticity theory was applied to model the relationship between the relaxation stresses and the displacements measured by ESPI during the evolution of the residual-stress-free state. We assessed the surface residual stress fields of indented bulk Cu; a Fe-Ni lead frame of 100 μm width; and 0.5 μm Au film. In the indented Cu, the normal and shear residual stresses around the indented point range from –1.7 GPa to 700 MPa and –800 MPa to 600 MPa, respectively, and the residual stress in the bending area of the Fe-Ni lead frame was estimated at 148 MPa and verified using beam-bending theory. In the Au film, tensile residual stresses are uniformly distributed from 500 MPa to 800 MPa as verified by X-ray diffraction.

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%.

Growth of surface flaws induced by the environment and machining stresses in unalloyed uranium

2005 ◽  
Vol 40 (2) ◽  
pp. 139-150 ◽  
Author(s):  
A Wallwork ◽  
G Burnell ◽  
S Morris ◽  
A Rowe ◽  
I Clarke ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Computer Modelling ◽  
Crack Nucleation ◽  
Initial Assessment ◽  
Residual Stress Field ◽  
Surface Residual Stress ◽  
Near Surface ◽  
Surface Features ◽  
Subsequent Propagation

Computer modelling techniques are used to predict the distribution of residual stresses in a machined uranium surface. The predictions are used to address the ageing of uranium exposed to inert gas based environments in terms of microcrack initiation and subsequent propagation. Metallographic observations of microcracking are used as the basis for the initial assessment of ageing behaviour. It is proposed that the near-surface residual stress field produced by machining influences the occurrence of microcracking. It is also suggested that corrosion-induced surface features act as initiation sites for microcracks, which begin to propagate by an environmentally assisted mechanism when the surface features reach a critical depth within the residual stress field of between 5 and 10 μm. However, the majority of the microcracks appear to arrest at about 150 μm. This behaviour is discussed in terms of the predicted threshold stress intensity for crack nucleation, uranium metallurgy, and the possible effects of crack coalescence on growth.

Influence of Final Hand Polishing Process on Surface Residual Stress Field of Japanese Sword

2013 ◽  
Vol 768-769 ◽  
pp. 492-499 ◽  
Author(s):  
Yoshihisa Sakaida ◽  
Hajime Yoshida ◽  
Shigeki Yashiro ◽  
Toshiyuki Murai
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Residual Stress Field ◽  
Polishing Process ◽  
Surface Residual Stress

scholarly journals Residual stresses near cold-expanded hole at different stages of high-cycle fatigue by crack compliance data

2021 ◽  
Vol 15 (56) ◽  
pp. 171-196
Author(s):  
Sviatoslav Eleonsky ◽  
Vladimir Pisarev ◽  
Mikhail Zajtsev ◽  
Mikhail Zichenkov ◽  
Marat Abdullin
Keyword(s):  
Residual Stress ◽  
High Cycle Fatigue ◽  
Low Cycle Fatigue ◽  
Speckle Pattern ◽  
Displacement Component ◽  
Electronic Speckle Pattern Interferometry ◽  
Cycle Fatigue ◽  
Residual Stress Field ◽  
Exit Surface ◽  
Plane Displacement

Experimental method for a characterization of high-cycle fatigue evolution of residual stress near cold-expanded hole is developed and implemented. The technique is based on simultaneous measurements of deformation response to narrow notch, inserted in residual stress field, on opposite specimen’s faces by electronic speckle-pattern interferometry (ESPI). Two-side measurements of notch opening displacements are performed when a single notch, emanating from cold-expanded hole edge, is inserted. The transition from in-plane displacement component to residual stress intensity factor (SIF) values follows from the relationships of modified version of the crack compliance method. The approach provides a difference in residual stress values referred to mandrel entrance and exit surface. Notches are inserted at different stages of low-cycle fatigue without applying external load. The results obtained describe fine nuances of residual stress evolution, which cannot be considered as monotonic relaxation.

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.

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.

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