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.

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.

Identification of Stress-Free State and Mapping of Residual Stress Fields by Laser Interferemetry

2004 ◽  
Vol 270-273 ◽  
pp. 1682-1687
Author(s):  
Dong Won Kim ◽  
Nak Kyu Lee ◽  
Kyoung Hoan Na ◽  
Dong Il Kwon
Keyword(s):  
Residual Stress ◽  
Free State ◽  
Stress Fields ◽  
Stress Free State

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.

Bivariate Fourier-series-based prediction of surface residual stress fields using stresses of partial points

2018 ◽  
Vol 24 (4) ◽  
pp. 979-995 ◽  
Author(s):  
Fengyun Wang ◽  
Kuanmin Mao ◽  
Shanguo Wu ◽  
Bin Li ◽  
Gang Xiao
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Fourier Series ◽  
Stress Field ◽  
Residual Stresses ◽  
Initial Stresses ◽  
Stress Fields ◽  
Critical Parameters ◽  
Generation Process ◽  
Surface Residual Stress

Surface residual stresses are critical parameters for evaluating the surface quality and can have an influence on many mechanical properties of solids. These stresses inevitably arise in almost all engineering components during manufacturing. However, most experimental and finite element approaches cannot obtain a complete surface residual stress field in a mechanical part. In this study, we propose a predictive method to determine surface stress fields, depending on residual stresses being self-equilibrating. The effectiveness of the approach is verified using a numerical surface of a beam example with ideal measurements and a casting–milling surface with experimental data. Using the proposed method, surface residual stress fields can be obtained from the stresses of a limited number of points including boundary points to solve the governing equations via a Fourier series bivariate polynomial as an Airy stress function with the Tikhonov regularization method. Our method does not require simulations of the residual stress generation process. This method is suitable for complex engineering parts where the manufacturing process is difficult to recreate in detail. The predicted stress field can be imported into a finite element solver as initial stresses to promote the design, manufacturing, and assessment of mechanical components.

Analysis of circumferentially welded thin-walled cylinders to study the effects of tack weld orientations and joint root opening on residual stress fields

2009 ◽  
Vol 223 (5) ◽  
pp. 1037-1049 ◽  
Author(s):  
N U Dar ◽  
E M Qureshi ◽  
A M Malik ◽  
M M I Hammouda ◽  
R A Azeem
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Arc Welding ◽  
Operating Conditions ◽  
Stress Fields ◽  
Welded Structures ◽  
Prime Concern ◽  
Thin Walled ◽  
Tack Weld ◽  
Welding Processes

In recent years, the demand for resilient welded structures with excellent in-service load-bearing capacity has been growing rapidly. The operating conditions (thermal and/or structural loads) are becoming more stringent, putting immense pressure on welding engineers to secure excellent quality welded structures. The local, non-uniform heating and subsequent cooling during the welding processes cause complex thermal stress—strain fields to develop, which finally leads to residual stresses, distortions, and their adverse consequences. Residual stresses are of prime concern to industries producing weld-integrated structures around the globe because of their obvious potential to cause dimensional instability in welded structures, and contribute to premature fracture/failure along with significant reduction in fatigue strength and in-service performance of welded structures. Arc welding with single or multiple weld runs is an appropriate and cost-effective joining method to produce high-strength structures in these industries. Multi-field interaction in arc welding makes it a complex manufacturing process. A number of geometric and process parameters contribute significant stress levels in arc-welded structures. In the present analysis, parametric studies have been conducted for the effects of a critical geometric parameter (i.e. tack weld) on the corresponding residual stress fields in circumferentially welded thin-walled cylinders. Tack weld offers considerable resistance to the shrinkage, and the orientation and size of tacks can altogether alter stress patterns within the weldments. Hence, a critical analysis for the effects of tack weld orientation is desirable.

Advanced Evaluation Methods of Residual Stress in Bioceramics Wear Surfaces

2010 ◽  
Vol 64 ◽  
pp. 43-48
Author(s):  
Giuseppe Pezzotti
Keyword(s):  
Residual Stress ◽  
Surface Stress ◽  
Electron Probe ◽  
Stress Fields ◽  
Fluorescence Probes ◽  
Surface Residual Stress ◽  
Hip Joints ◽  
Polycrystalline Alumina ◽  
Probe Size ◽  
F Center

Photo- and electro-stimulated probes have been employed for quantitatively evaluating highly graded residual stress fields generated at the surface of alumina hip joints. Optical calibrations revealed large differences in probe size, which strongly affected the detected magnitude of residual stress. A comparison between the responses of Raman and fluorescence probes in polycrystalline alumina showed that the depth of those probes spread to an extent in the order of the tens of microns even with using a confocal probe configuration. On the other hand, the electro-stimulated luminescence emitted by oxygen vacancy sites (F+ center) in the alumina lattice represented a suitable choice for confining to a shallow volume the stress probe. The electron probe enabled confining the measurement depth to the order of the tens of nanometers. Maps of surface residual stress were collected on both main-wear and non-wear zones of an alumina femoral head. A comparison among stress maps taken at exactly the same location, but employing different probes, clarified the averaging probe effects on surface stress magnitude.

Study on the Correlativity between Grinding Parameters and Surface Residual Stresses in Ceramic

2008 ◽  
Vol 375-376 ◽  
pp. 480-484 ◽  
Author(s):  
Guang Xiu Zhang ◽  
Bin Lin ◽  
Zhen Peng Shi
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Mechanical Effect ◽  
Diffraction Measurement ◽  
Depth Of Penetration ◽  
Surface Residual Stress ◽  
Grinding Parameters ◽  
Surface Residual Stresses ◽  
Element Simulation

The generation and distribution of workpiece surface and sub-surface residual stress were predicted through the dynamic finite element simulation of the grinding ceramic process. The base of the simulation is that the thermo elastic-plastic finite element theory and the coupling of grinding forces and temperature were adopted. The results obtained from X-ray diffraction measurement compared well with the values calculated from theory. The correlation between grinding parameters and the ceramic residual stresses was investigated. The research results show that the normal grinding force is the primary factor responsible for the generation of residual stress in grinding ceramic. The mechanical effect of the grains is to affect the magnitude, the depth of penetration and the gradient of the residual stresses.

The Characteristics of Surface Residual Stresses by Plane Grinding Invar and the Effects of Them on Structural Stability

2008 ◽  
Vol 53-54 ◽  
pp. 293-298
Author(s):  
Y.P. Qiao ◽  
Ren Ke Kang ◽  
Zhu Ji Jin ◽  
Dong Ming Guo
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Residual Stresses ◽  
Structure Stability ◽  
Tension Stress ◽  
Surface Residual Stress ◽  
Disk Model ◽  
Surface Residual Stresses ◽  
The Stability ◽  
Working Procedure

Invar 36 alloy is widely used in manufacturing instruments because of its minimal thermal expansion coefficient. As an important material for the components of precision or super-precision instruments, the process methods for Invar and the structure stability after its machining is necessary. In this paper, the residual stresses of the Invar samples after plane grinding were measured. The experimental results indicate that clear tension stress exists in the surface of Invar alloy along the grinding direction, while, on the cross direction, the states of surface residual stresses are complicated and affected by the parameters of grinding. A typical disk model has been calculated and analyzed by Finite Element Method (FEM), and the deformation caused by surface residual stress was presented. Finally, the effect of grinding as final working procedure on the stability of Invar structure was estimated.

Modeling and Measurement of Residual Stresses along the Process Chain of Autofrettaged Components by Using FEA and Hole-Drilling Method with ESPI

2013 ◽  
Vol 768-769 ◽  
pp. 79-86 ◽  
Author(s):  
Horst Brünnet ◽  
Dirk Bähre ◽  
Theo J. Rickert ◽  
Dominik Dapprich
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Speckle Pattern ◽  
Residual Stress Distribution ◽  
Electronic Speckle Pattern Interferometry ◽  
Hole Drilling ◽  
Element Analysis ◽  
Hole Drilling Method ◽  
Drilling Method

The incremental hole-drilling method is a well-known mechanical measurement procedure for the analysis of residual stresses. The newly developed PRISM® technology by Stresstech Group measures stress relaxation optically using electronic speckle pattern interferometry (ESPI). In case of autofrettaged components, the large amount of compressive residual stresses and the radius of the pressurized bores can be challenging for the measurement system. This research discusses the applicability of the measurement principle for autofrettaged cylinders made of steel AISI 4140. The residual stresses are measured after AF and after subsequent boring and reaming. The experimental residual stress depth profiles are compared to numerically acquired results from a finite element analysis (FEA) with the software code ABAQUS. Sample preparation will be considered as the parts have to be sectioned in half in order to access the measurement position. Following this, the influence of the boring and reaming operation on the final residual stress distribution as well as the accuracy of the presented measurement setup will be discussed. Finally, the usability of the FEA method in early design stages is discussed in order to predict the final residual stress distribution after AF and a following post-machining operation.

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%.

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