Abstract
This paper focuses on the analysis of the plasticity effect in the measurement of the residual stress by the hole-drilling method. Relaxed strains were evaluated by the computational simulation of the hole-drilling experiment using the finite element method. Errors induced by the yielding were estimated for uniaxial tension, plane shear stress state and equi-biaxial stress state at various magnitudes of residual stress uniformly distributed along the depth. The correction of the plasticity effect in the evaluation of residual stress was realized according to the method proposed by authors from the University in Pisa, which was coded in MATLAB. Results obtained from the MATLAB script were compared to the original input data of the hole-drilling simulation and discussed. The analyses suggested that the plasticity effect is negligible at the ratio of applied equivalent stress to yield stress, being 0.6, and that the correction of the plasticity effect is very successful at the previous ratio, being 0.9. Failing to comply with the condition of the strain gauge rosette orientation according to the principal stresses directions causes an increase in the relative error of corrected stresses only for the case of uniaxial tension. It affects the relative error negligibly for the plane shear and equi-biaxial stress states.
Highlights
Almost all technological operations induce residual stress
Where σeq,e is elastically evaluated equivalent stress by the ASTM standard, σeq,i is the equivalent residual stress, when the plastic deformation is induced on the cylindrical surface of the drilled hole, Re is yield stress, Ω is the biaxiality ratio, z is the hole depth and D is the mean diameter of the strain gauge rosette
The main for goal of the research investigate thewhere efficiency of orientation the plasticity in the hole-drilling method industrial practice;was that to means for states, correct of correction in the hole-drilling method for industrial practice; that means for states, where correct the strain gauge rosette is not always guaranteed or the yield strength of material may be unknown
Summary
Almost all technological operations induce residual stress. These might occur during the operation of the structure. Its existence negatively influences the generation of various limit states regarding the component failure as well as undesirable changes in the structure shape. There is the demand for finding the magnitude of residual stress and adopting measures for their minimization. One of the most frequent methods for measuring residual stress is the semi-destructive hole-drilling method. The drilling of a hole (blind or through) causes the redistribution of residual stress around it (Figure 1). The relaxed strains are measured on the component’s surface by a strain gauge rosette, usually consisting of three resistive grids.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
