scholarly journals High Accurate Residual Stress Evaluation by Deep Hole Drilling Technique Considering Three-dimensional Stress Fields

2013 ◽  
Vol 31 (4) ◽  
pp. 124s-128s ◽  
Author(s):  
Houichi Kitano ◽  
Shigetaka Okano ◽  
Masahito Mochizuki
Author(s):  
Amir-Hossein Mahmoudi ◽  
David J. Smith ◽  
Chris E. Truman ◽  
Martyn J. Pavier

The modified deep hole drilling technique (iDHD) has been developed to allow near yield residual stresses to be measured and has been validated for axisymmetric residual stress fields. In the present investigation, the application of the iDHD technique was extended to non-axisymmetric stress fields. First, a finite element simulation of the iDHD technique was carried out to demonstrate its effectiveness at measuring near yield residual stress. Experimental measurements were then carried out on shrink fit specimens to investigate the performance of the technique in practice. These shrink fit specimens were assembled in such a way that either axisymmetric or non-axisymmetric stress fields could be generated. The results indicated that the iDHD technique is capable of measuring non-axisymmetric residual stresses in presence of plasticity.


Author(s):  
Amir H. Mahmoudi ◽  
David J. Smith ◽  
Chris E. Truman ◽  
Martyn J. Pavier

Accurate evaluation of residual stress is essential if is to be taken into account in structural integrity assessments. For thick components, many non-destructive residual stress measurement techniques cannot be used since they are unable to measure the stresses deep within the component. Measurement techniques which involve mechanical strain relief through material removal are the only alternative. Recently, it has been found that these techniques may fail to measure the stresses correctly when highly triaxial stresses are present because plastic redistribution can occur when the material removal is carried out. The Deep Hole Drilling technique is a very powerful method to measure the stresses within very thick engineering components. However, it can suffer from high levels of plasticity and lead to inaccurate results. It is shown in the present research that the effect of plasticity on the measured stresses can be eliminated. In the present work, the effect of gauge volume on the plasticity effect is investigated.


Author(s):  
Gang Zheng ◽  
Sayeed Hossain ◽  
Feng Shen ◽  
Chris Truman

The aim of the present study was to utilize a complex residual stress generated within a welded circular disc to further investigate the standard deep-hole drilling (DHD) technique and the newly developed over-coring deep-hole drilling (oDHD) technique in accurately measuring residual stresses well over yield stress. Finite Element Analysis (FEA) was used to optimize and extend the deep-hole drilling technique and improve its accuracy. The standard DHD procedure involves 4 steps. (1) A reference hole is gun-drilled through the component. (2) The internal diameter of the reference hole is measured at different angular positions through the depth of the component. (3) A cylindrical section with the reference hole as its longitudinal axis is trepanned free from the component. (4) Finally, the relaxed internal diameter is re-measured at the same angular positions and the same depths. The drilling, trepanning procedures and the parameters of the deep-hole drilling technique were all studied in detail to optimize the technique. Comparison is made between the FEA predicted residual stress in the weld, the measurements and the reconstructed residual stresses of the measurements. The close correlations confirmed the suitability of new modifications made in the deep-hole drilling technique to account for plasticity when measuring near yield residual stresses present in a component.


Strain ◽  
2011 ◽  
Vol 47 (1) ◽  
pp. 62-74 ◽  
Author(s):  
D. M. Goudar ◽  
C. E. Truman ◽  
D. J. Smith

Author(s):  
Masahito Mochizuki ◽  
Houichi Kitano ◽  
Shigetaka Okano

The deep hole drilling technique (DHD) has received much attention in recent years as a method for measuring through-thickness residual stresses. However, the accuracy of the measurements of residual stresses by the DHD technique is affected by the deformation produced in the DHD process. In this study, the effects of the deformation are investigated in detail by FE analysis. Then, a new procedure for high accuracy evaluation of residual stresses by the DHD technique is discussed. In addition, the procedure are applied to the evaluation of some inner stress fields.


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