Residual Stress Evaluation by the Hole-Drilling Method With Off-Center Hole: An Extension of the Integral Method

1997 ◽  
Vol 119 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Dario Vangi

With the incremental hole-drilling method, it is possible to evaluate residual stress variations with depth, acquiring strain values for each step by strain gages. These data can be processed by the integral method. Usually strain gages are not spaced equidistant from the hole center nor arranged in the radial direction, due to practical difficulties in drilling a centered hole. In this study we present a development of the integral method for evaluating stress variations with depth in the specimen for eccentric blind hole cases. The results can be extended and adopted for use with a non-conventional strain gage array.

2014 ◽  
Vol 996 ◽  
pp. 283-288 ◽  
Author(s):  
Esther Held ◽  
Simone Schuster ◽  
Jens Gibmeier

The incremental hole-drilling method is a widely used technique to determine residual stress depth profiles in technical components. Its application is limited in respect to the components geometry, for instance the components thickness. In this paper, a direct correction of the measured strain relaxations is proposed to consider the impact of deviant geometries, here the component thickness, on the residual stress evaluation that moreover, allows the application of commercially available evaluation software. The herein proposed approach is based on finite element simulation of the incremental hole drilling. The simulated strain relaxations for thin metal sheets are evaluated with an algorithm as used in commercially available evaluation software (i) for uncorrected data as well as (ii) for strain data corrected by the proposed correction procedure. It is shown that the correction approach leads to a significant improvement of the measurement accuracy. Further, by means of the approach residual stress depth profiles in thin metal sheets can be as usual determined using commercial evaluation software for the incremental hole-drilling method regardless of the algorithm used, i.e. differential or integral.


2002 ◽  
Vol 124 (3) ◽  
pp. 349-353 ◽  
Author(s):  
H. Walaszek ◽  
H. P. Lieurade ◽  
C. Peyrac ◽  
J. Hoblos ◽  
J. Rivenez

The good control of residual stress level in mechanical components is an important factor, particularly for a good fatigue strength of these components. This paper presents advances obtained at the technical center for mechanical engineering industries (CETIM) in the field of development of an ultrasonic method for stress measurements. This method is potentially advantageous because it is nondestructive, has good portability, and is easy to use. In the paper are discussed the results obtained with ultrasonics on steel welded plate, and a comparison is made with stress measurement obtained by incremental hole-drilling method, and X-ray diffraction. These results are also validated by thermal relaxation of the plates. The paper discusses also the microstructure influence on ultrasonic measurements and methods for adjusting the ultrasonic measurements to improve the agreement with results obtained from other techniques. In conclusion is emphasized the interest for studying the ability of the ultrasonic residual stress measurement method in different industrial cases.


2016 ◽  
Vol 827 ◽  
pp. 117-120
Author(s):  
Jaroslav Vaclavik ◽  
Stanislav Holy ◽  
Jiří Jankovec ◽  
Petr Jaros ◽  
Otakar Weinberg

The method for residual stress measurement using through the hole drilling and investigation of the residual stresses relief with the help of incremental layers removing is presented. Drilling the rosette-hole from the opposite side – the inverse layers removing – have to be used for evaluation of residual stress near the back side of the object wall in cases when this surface is inaccessible for any hole-drilling instrument. The strain gauge rosette is installed on the opposite side of the drilled wall and a new mechanical task of incremental layers removal must be solved. The calibration constants for residual stress evaluation of HBM RY21 type rosette for this case were derived using numerical modeling by FEA and its experimental verification.


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