Calibration of residual stress measurements obtained from EDM hole drilling method using physical material properties

2008 ◽  
Vol 24 (12) ◽  
pp. 1462-1469 ◽  
Author(s):  
H. T. Lee ◽  
C. Liu
2013 ◽  
Vol 768-769 ◽  
pp. 174-181 ◽  
Author(s):  
David von Mirbach

Two commonly used mechanical methods for the determination of residual stresses are the hole-drilling method and the ring-core method, which can be regarded as semi-destructive. The most restricting limitation for the general applicability of both methods, according to the current state of science and technology, is the fact that the scope for relatively low residual stress under 60% of the yield stress is limited.This is a result of the notch effect of the hole or ring core, which leads to a plastification around and on the bottom of the hole and ring shaped groove already at stresses well below the yield stress of the material. The elastic evaluation of the resulting plastic strains leads consequently to an overestimation of the delineated residual stresses. In this paper the influence of elastic-plastic material properties no the specific calibration function for the hole-drilling method using the differential method is studied, and the method of adaptive calibration functions is presented.


2015 ◽  
Vol 55 (9) ◽  
pp. 1745-1756 ◽  
Author(s):  
R. Blödorn ◽  
M. R. Viotti ◽  
R. B. Schroeter ◽  
A. Albertazzi

2013 ◽  
Vol 768-769 ◽  
pp. 150-157 ◽  
Author(s):  
Emilio Valentini ◽  
Alessio Benincasa ◽  
Ciro Santus

This paper shows a large validation activity of the strain gage Hole Drilling Method. The residual stress measurements can not be validated easily, unless with Round Robin activity and/or comparison with other residual stress measurements such as X-ray diffraction. An accurate validation procedure is reported in the present paper, using abending test rig. The bending stress experimentally simulated a residual stress (known with uncertainty lower than 1%) that was considered as the reference stress distribution. The results showed very accurate measurement in terms of relaxed strain distributions, that were compared with the prediction obtained with the Influence Function technique. The differences were in the order of 0.5 microepsilon as standard deviation on a large number of tests. The bending stress prediction was consequently very accurate and the stress differences were as small as 1 MPa showing the accuracy potentiality of the method.


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