Improved Blind-hole Method of Measuring Residual Stress of Steel Plates

The basic principle and disadvantage of measuring residual stress by traditional blind-hole method were explained. And the improved blind-hole method was also introduced: first drilling a small hole on the work piece, then recording the strain change while expanding the hole repeatly, finally calculating the stress value according to it. The specimens were prefabricated for the experiment, and the residual stress of the specimens was measured simultaneously by the traditional and improved blind-hole method. The results show that the improved method could effectively reduce the additional stress caused by drilling, and obtain more accurate stress value.