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.

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.

Determination of surface residual stresses in carburised AISI 8620 steel by the magnetic Barkhausen noise method

2020 ◽  
Vol 62 (7) ◽  
pp. 416-421
Author(s):  
T Kaleli ◽  
C Hakan Gür
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Fatigue Behaviour ◽  
Barkhausen Noise ◽  
Magnetic Barkhausen Noise ◽  
Surface Residual Stress ◽  
Technical Requirements ◽  
Surface Residual Stresses

Management of the residual stress state is vital for the design and production stages of carburised components in order to satisfy the technical requirements related to performance, fatigue behaviour and useful lifetime. This enforces the use of practical, reliable and time- and cost-effective stress measurement methods by manufacturers. This study aims to investigate the efficiency of the magnetic Barkhausen noise (MBN) method in rapid non-destructive determination of surface residual stresses in carburised steels. A series of AISI 8620 steel specimens with different residual stress states was prepared by altering the carburising and subsequent tempering parameters. The specimens were characterised through scanning electron microscopy (SEM) investigations and hardness measurements, and the surface residual stresses were determined using both the MBN and X-ray diffraction (XRD) methods. The results show that a good correlation exists between surface residual stress and the parameters derived from the MBN signals.

Micro-slotting technique for reliable measurement of sub-surface residual stress in Ti-6Al-4V

2018 ◽  
Vol 53 (6) ◽  
pp. 389-399 ◽  
Author(s):  
Elizabeth Burns ◽  
Joseph Newkirk ◽  
James Castle
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Image Correlation ◽  
X Ray Diffraction ◽  
Surface Residual Stress ◽  
Near Surface ◽  
X Ray ◽  
Measurement Volume ◽  
Surface Residual Stresses

Micro-slotting, a relaxation residual stress measurement technique, has recently been shown to be an effective method for measuring local residual stresses in a variety of materials. The micro-slotting method relies on a scanning electron microscope–focused ion beam system for milling and imaging, digital image correlation software to track displacements due to residual stress relaxation after milling, and finite element analysis for displacement–stress correlation and calculation of the original stress state in the imaged region. The high spatial resolution of the micro-slotting method makes it a promising technique for obtaining near-surface residual stress data in Ti-6Al-4V components for input into fatigue life models and crack growth simulations. However, use of the micro-slotting method on this alloy has yet to be evaluated against more established measurement techniques. In this study, spatially resolved sub-surface residual stress measurements were obtained on shot peened and low-stress surface-machined Ti-6Al-4V planar coupons using the micro-slotting method and were compared to measurements obtained using the conventional X-ray diffraction depth profiling technique. The sub-surface measurements were in good agreement for the shot peened sample. Observed differences in the measured near-surface residual stresses on the surface-machined sample were attributed to the larger measurement volume of the X-ray diffraction method, suggesting that the micron-sized measurement volume of the micro-slotting method may be more suitable for capturing shallow stress profiles and steep stress gradients. Prior to performing the micro-slotting measurements, finite element modeled displacements were used to verify the measurement procedure and to address uncertainties in the milled slot geometries. The results of this study demonstrated the validity of the micro-slotting procedure and established the technique as a reliable method for measuring sub-surface residual stresses in Ti-6Al-4V.

Study Progress on Grinding Surface Residual Stresses for Nano-Ceramic Coatings

2013 ◽  
Vol 753-755 ◽  
pp. 277-280 ◽  
Author(s):  
Wei Xiang Liu
Keyword(s):  
Residual Stress ◽  
High Hardness ◽  
Ceramic Materials ◽  
Ceramic Coatings ◽  
Grinding Process ◽  
Monitoring And Control ◽  
Surface Residual Stress ◽  
Surface Residual Stresses ◽  
Process Monitoring And Control ◽  
Grinding Mechanism

Nano-ceramic materials had high hardness and wear resistance. Combined with current technology and cost saving, nanostructured coatings technology were carried out, using HVOF ( high velocity oxygen fuel) or plasma spraying technique can obtain high quality ceramic coating on metal substrate. Ceramic coatings produced cracks in the grinding due to grinding surface residual stress. the coatings grinding surface residual stress of engineering ceramics have been researched, grinding surface residual stress in the nanostructured ceramic coatings are being researched. the researches in this field include grinding process modeling, abrasives and grinding parameters, grinding process monitoring and control and realization of the software, the grinding mechanism and grinding damage on the surface, grinding force prediction, on-line detection, grinding on nanocoating material is a multivariable complex process.

The Compliance Method for Measurement of Near Surface Residual Stresses—Analytical Background

1994 ◽  
Vol 116 (4) ◽  
pp. 550-555 ◽  
Author(s):  
M. Gremaud ◽  
W. Cheng ◽  
I. Finnie ◽  
M. B. Prime
Keyword(s):  
Numerical Simulation ◽  
Residual Stresses ◽  
Random Errors ◽  
Residual Stress Field ◽  
Near Surface ◽  
Surface Residual Stresses ◽  
Zero Shift ◽  
Stress States ◽  
The Stability ◽  
Piecewise Functions

Introducing a thin cut from the surface of a part containing residual stresses produces a change in strain on the surface. When the strains are measured as a function of the depth of the cut, residual stresses near the surface can be estimated using the compliance method. In previous work, the unknown residual stress field was represented by a series of continuous polynomials. The present paper shows that for stress states with steep gradients, superior predictions are obtained by using “overlapping piecewise functions” to represent the stresses. The stability of the method under the influence of random errors and a zero shift is demonstrated by numerical simulation.

Residual Stresses in Self-Curing Bone Cement During Hip Arthroplasty

2003 ◽  
Author(s):  
Chaodi Li ◽  
Ying Wang ◽  
James J. Mason
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Hip Arthroplasty ◽  
Experimental Tests ◽  
Cement Mantle ◽  
Joint Arthroplasty ◽  
Residual Stress Distribution ◽  
Bone Cements

Bone cements are widely used to fix prostheses into bones for joint arthroplasty. During cement curing in total hip arthroplasty, residual stresses are introduced in the cement mantle. A finite element method was developed to predict such residual stress built-up. The effects of curing history on the residual stress distribution were investigated. Results showed that the predictions of the residual stresses agreed with the experimental tests very well. The residual stress build-up was shown to depend on the curing history. By preheating the prosthesis stem prior to implantation, a desired low level residual stress at the critical interface was obtained.

Numerical Simulation of Residual Stresses Induced from Shot Peening with Finite Element Method

2013 ◽  
Vol 433-435 ◽  
pp. 1898-1901
Author(s):  
Li Juan Cao ◽  
Shou Ju Li ◽  
Zi Chang Shangguan
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Residual Stress ◽  
Surface Layer ◽  
Residual Stresses ◽  
Shot Peening ◽  
Target Material ◽  
Residual Stress Field ◽  
State Of Stress ◽  
Compressive Residual Stresses

Shot peening is a manufacturing process intended to give components the final shape and to introduce a compressive residual state of stress inside the material in order to increase fatigue life. The modeling and simulation of the residual stress field resulting from the shot peening process are proposed. The behaviour of the peened target material is supposed to be elastic plastic with bilinear characteristics. The results demonstrated the surface layer affected by compressive residual stresses is very thin and the peak is located on the surface.

Influence of Cooling Intensity on Residual Stress State of TIG Dressing Zone for T-Joint Welded Toe

2011 ◽  
Vol 148-149 ◽  
pp. 1289-1294 ◽  
Author(s):  
Kun Zhou ◽  
Chun Yuan Shi ◽  
Cheng Jin
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Stress State ◽  
Residual Stresses ◽  
Residual Stress Distribution ◽  
Residual Stress State ◽  
Cooling Intensity ◽  
Stress Layer ◽  
Spray Treatment

Using finite element method, the residual stress distribution of the TIG dressed welded toe followed by spray treatment with different cooling intensity was calculated. And the residual stresses of welded toe were also measured by using the blind-hole method. The results indicate that with the increase of cooling intensity, the longitudinal residual stresses in welded toe are gradually transited from tensile residual stresses to compressive ones, and there is no significant change for transverse residual stresses, and the depth of compressive stress layer increases at the welded toe region.

Modeling Residual Stresses in Superduplex Stainless Steel Welded Pipes Using the Finite Element Method

2013 ◽  
Vol 758 ◽  
pp. 1-10
Author(s):  
Fabiano Rezende ◽  
Luís Felipe Guimarães de Souza ◽  
Pedro Manuel Calas Lopes Pacheco
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Welding Process ◽  
Welding Parameters ◽  
Superduplex Stainless Steel ◽  
Mechanical Components ◽  
Element Method

Welding is a complex process where localized and intensive heat is imposed to a piece promoting mechanical and metallurgical changes. Phenomenological aspects of welding process involve couplings among different physical processes and its description is unusually complex. Basically, three couplings are essential: thermal, phase transformation and mechanical phenomena. Welding processes can generate residual stress due to the thermal gradient imposed to the workpiece in association to geometric restrictions. The presence of tensile residual stresses can be especially dangerous to mechanical components submitted to fatigue loadings. The present work regards on study the residual stress in welded superduplex stainless steel pipes using experimental and a numerical analysis. A parametric nonlinear elastoplastic model based on finite element method is used for the evaluation of residual stress in superduplex steel welding. The developed model takes into account the coupling between mechanical and thermal fields and the temperature dependency of the thermomechanical properties. Thermocouples are used to measure the temperature evolution during welding stages. Instrumented hole drilling technique is used for the evaluation of the residual stress after welding process. Experimental data is used to calibrate the numerical model. The methodology is applied to evaluate the behavior of two-pass girth welding (TIG for root pass and SMAW for finishing) in 4 inch diameter seamless tubes of superduplex stainless steel UNS32750. The result shows a good agreement between numerical experimental results. The proposed methodology can be used in complex geometries as a powerful tool to study and adjust welding parameters to minimize the residual stresses on welded mechanical components.

Control of Surface Finishing Residual Stresses in Magnetic Recording Head Materials

1988 ◽  
Vol 110 (1) ◽  
pp. 87-92 ◽  
Author(s):  
S. Chandrasekar ◽  
B. Bhushan
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Magnetic Recording ◽  
Surface Finishing ◽  
Recording Head ◽  
Surface Residual Stresses ◽  
Mechanical And Physical Properties ◽  
Magnetic Recording Head ◽  
Processing Techniques

Surface finishing of magnetic recording head materials, such as ferrites, by diamond grinding and lapping results in a residual compressive stress on the surface. Residual stresses alter the magnetic properties of the ferrite causing the recording head performance to deteriorate. Hence, they need to be minimized. This paper considers the role of two processing techniques—annealing and chemical lapping—in controlling residual stress in ferrites. The effect of these processing techniques on various mechanical and physical properties of finished ferrites and the mechanism of residual stress control are discussed.

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