ON THE ERROR ANALYSIS OF RESIDUAL-STRESS MEASUREMENTS BY THE HOLE-DRILLING METHOD

In this paper, an error analysis is carried out to discuss two important parameters that influence the accuracy in the measurement of residual stress by the hole-drilling technique. The first is the error associated with zero strain phenomenon that occurs for certain orientations of the strain gauges. A rigorous condition for zero strain point is given and measurement accuracy is discussed when the zero strain point phenomenon occurs. Secondly, the calculated residual stress field affected by the methods chosen for the estimation and calibration of the relieved strain coefficients. The errors as associated with the estimation of the relieved strain coefficients are also discussed along with their useful range for the calculation of the residual stress field.