Experimental and Numerical Strategies to Consider Hole Eccentricity for Residual Stress Measurement with the Hole Drilling Method

Abstract

Abstract For the analysis of residual stress depth distributions the semi-destructive incremental hole drilling method is the process of choice for quick and cost-efficient measurements. Nevertheless, the experimental execution has to be carried out carefully. Minor deviations of the ideal case, for example incorrect depth setting or eccentricity of the drilled hole to the center of the applied strain gage rosette can result in large errors or invalid results. In this paper two different strategies are presented, in order to take eccentricity into consideration. The first strategy requires a specific strain gage rosette consisting of eight single strain gages arranged at 45° angle to each other. The second strategy works with standard strain gage rosettes, but with calibration functions modified for the eccentric case. Both strategies are able to reveal and to correct the consequences of eccentricity on the results of stress analyses. In order to improve the quantitative accuracy of residual stress measurements the latter strategy should be preferred.