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

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.

2008 ◽  
Vol 53-54 ◽  
pp. 293-298
Author(s):  
Y.P. Qiao ◽  
Ren Ke Kang ◽  
Zhu Ji Jin ◽  
Dong Ming Guo

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.


2013 ◽  
Vol 433-435 ◽  
pp. 1898-1901
Author(s):  
Li Juan Cao ◽  
Shou Ju Li ◽  
Zi Chang Shangguan

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.


Author(s):  
Nazrul Islam ◽  
Tasnim Hassan

Earlier studies [1] showed that the ANSYS software package customized with an advanced rate-independent constitutive model was unable to simulate some of the low-cycle fatigue responses of elbow components. Hence, simulations are performed to investigate the influence of manufacturing and welding residual stresses on elbow low-cycle fatigue responses. The sequentially coupled thermo-mechanical finite element analysis is performed to determine the initial residual stress states in elbows due to the elbow manufacturing processes and welding of elbows to straight pipes. Real-time girth-welding processes are taken into account to simulate the welding induced residual stress field. Incorporating these initial residual stresses in the computations, low-cycle fatigue and strain ratcheting responses are simulated by ANSYS. The simulation responses demonstrate that the influence of manufacturing and welding residual stresses in elbows on its low-cycle fatigue responses is negligible. Hence, the question remains what is missing in the simulation models that some of the elbow low-cycle fatigue responses cannot be simulated.


2014 ◽  
Vol 996 ◽  
pp. 598-602
Author(s):  
Frédéric Valiorgue ◽  
Mathieu Girinon ◽  
Eric Feulvarch ◽  
Joël Rech ◽  
Philippe Gilles

Numerical simulation of turning is still one of the best solutions to understand and improve such a process. Since many years, researchers have tried to use several numerical approaches to go round the difficulties and to set up reliable models (Lagrangian, ALE,…). Currently no perfect complete solution is available and it is time to introduce dedicated models prone to simulate partially the phenomena in order to reach specific conditions linked with real industrial problematics. This paper will present a 3D local global method set up to predict surface residual stresses in finish turning. This approach uses two kinds of simulations. A first one that allows reaching thermo mechanical steady state around the cutting edge and the chip area. A second one which sequences the application of the extracted thermo mechanical fields onto the real workpiece surface. The obtained results concerning the residual stresses fields will then be compared with the ones recorded experimentally.


2009 ◽  
Vol 15 ◽  
pp. 109-114 ◽  
Author(s):  
G. Urriolagoitia-Sosa ◽  
E. Zaldivar-González ◽  
J.M. Sandoval Pineda ◽  
J. García-Lira

The interest on the application of the shot peening process to arrest and/or delay crack growth is rising. The main effect of the shot peening technique is to introduce a residual stress field that increases the working life of mechanical components. In this paper, it is presented the numerical simulation (FEM) of the shot peening process and the effect of introducing a residual stress field. Besides, the consequence of changing the sizes of the impacting ball is analyzed. This work also used the Crack Compliance Method (CCM) for the determination of residual stresses in beams subjected to a numerical simulation of a shot peening process. The numerical results obtained provide a quantitative demonstration of the effect of shot peening on the introduction of residual stresses by using different sizes of impacting balls and assess the efficiency of the CCM.


2010 ◽  
Vol 24-25 ◽  
pp. 253-259 ◽  
Author(s):  
G. Urriolagoitia-Sosa ◽  
B. Romero-Ángeles ◽  
Luis Héctor Hernández-Gómez ◽  
G. Urriolagoitia-Calderón ◽  
Juan Alfonso Beltrán-Fernández ◽  
...  

The understanding of how materials fail is still today a fundamental research problem for scientist and engineers. The main concern is the assessment of the necessary conditions to propagate a crack that will eventually lead to failure. Nevertheless, this kind of analysis tends to be more complicated, when a prior history in the material is taken into consideration and it will be extremely important to recognize all the factors involved in this process. In this work, a numerical simulation of the introduction of residual stresses, which change the crack initiation conditions, in a modified compact tensile specimen to change the condition of crack initiation is presented. Four numerical analyses were carried out; an initial evaluation was performed in a specimen without a crack and it was used for the estimation of a residual stress field produced by an overload; three more cases were simulated and a crack was introduced in each specimen (1 mm, 5 mm and 10 mm, respectively). The overload was then applied to set up a residual stress field into the component; furthermore, in each case the crack compliance method (CCM) was applied to measure the induced residual stress field. By performing this numerical simulation, the accuracy of the crack compliance method can be evaluated. On the other hand, elastic-plastic finite element analysis was utilized for the residual stress estimation. The numerical analysis was based on the mechanical properties of a biocompatible material (AISI 316L). The obtained results provided significant data about diverse factors, like; the manner in which a residual stress field could modify the crack initiation conditions, the convenient set up for induction of a beneficial residual stresses field, as well as useful information that can be applied for the experimental implementation of this research.


1994 ◽  
Vol 116 (1) ◽  
pp. 1-7 ◽  
Author(s):  
W. Cheng ◽  
I. Finnie ◽  
M. Gremaud ◽  
M. B. Prime

In previous work it has been shown that near surface residual stresses may be deduced from surface strains produced by making a cut of progressively increasing depth. The process of electric discharge wire machining (EDWM), by providing very narrow cuts, greatly improves the ability of the method to resolve a stress gradient near the surface. However, the EDWM process may also introduce residual stresses. In the present work a model for estimating the influence of EDWM is presented, and a procedure for eliminating its effect on residual stress measurement is developed. Experimental results validate the theoretical approach.


Materials ◽  
2017 ◽  
Vol 10 (6) ◽  
pp. 593 ◽  
Author(s):  
Ebrahim Harati ◽  
Leif Karlsson ◽  
Lars-Erik Svensson ◽  
Thilo Pirling ◽  
Kamellia Dalaei

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