MEASUREMENT OF K_(IC) OF MEDIAN OR LOW STRENGTH STEEL USING ROUND BARS WITH CIRCUMFERENCIAL CRACK
采用环状裂纹圆棒试样测定中低强度钢的断裂韧度

The size effect of tension round bars with circumferencial crack was described and used to measure the planestrain fracture toughness K_(IC) of median or low strength steel. The size of cylindrical specimen. required for K_(IC) measurement is much smaller than that of standard specimen. The J-integral values of the cylin- drical specimens were calculated to characterize the size effect. The finite element calculation and fracture morphology analysis have been conducted to explain the fact that smaller cylindrical specimen could be used to measure K_(IC) of median or low strength steel.