Abstract
It is necessary to investigate the crack growth behavior of large deformation under the complex loading in order to maintain reliability of actual structures subjected to seismic forces. Therefore, a large deformation torsion fatigue testing machine is developed. Then, the crack growth behavior of notched plate specimens of stainless steel, SUS316L, used for piping is observed. The fatigue crack growth behavior of surface changed from the shear mode to the opening mode. As a result of fracture surface observation, it is found from crack front geometry that crack growth rate of surface is faster than that of inside. J-integral range of crack front for SUS316L is calculated by finite element method and crack growth characteristic is evaluated by J-integral range. These results corresponded to the mode I crack growth characteristics.
