engleski

Measurement of residual stress by the hole-drilling method: differences in predicted stress distribution due to applied calculation method

The objective of this investigation was to compare residual stresses predicted by different calculation methods. An overall estimation of the measurement error is provided by measurement of the relaxed strains on a known stress distribution. In theory the integral and power series calculation methods give the absolute accurate estimations. In a discrete case, their accuracy is not absolute and decreases with a reduced number of points analyzed. With increased accuracy, these methods, are increasingly sensitive to measurement errors. The equivalent uniform stress method and it's modification, average stress method are theoretically not correct and with stresses which experienced big variation at the analyzed depth, they give significant error in the predicted stress distribution. This theoretical shortcoming, along with a reduced sensitivity of the calculation method, with respect to the stress distribution, also reduces the respective sensitivity on the measurement errors.The conclusion is that with this measurement technique, it is more appropriate to estimate residual stresses by less sensitive calculation methods.

residual stress; hole drilling; calculation methods

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