Dynamic stress analysis of a three-dimensional solid body (Dynamic stress concentration factor around a spherical cavity in a cylindrical bar)

Abstract

The reflection and interference of stress-waves play an important role in dynamic cases. It is very desirable to study the time variation of the stress distribution and especially the dynamic stress concentration factor in three-dimensional solid bodies. Hence, we have already reported the dynamic stress concentration factor around a spherical cavity in a smoothed cylindrical bar. Further, we have analyzed the stress propagation and the dynamic stress concentration phenomena around a spherical cavity in the various grooved cylindrical bars by utillizing the strain gage method and also the finite element method. Emphasis was laid on the dynamic stress concentration analysis of bodies with inner cavities, such as those often found in welded parts or castings. We found that the three-dimensional dynamic stress concentration factors obtained by the present two methods are in general agreement. In the small radius grooved cylindical bars, the dynamic stress concentration factor inside the inner spherical cavity does not give a larger variation, and at the circular notch the root becomes larger, with increasing diameter of the cavity. On the other hand, when the circular notch radius of the grooved cylindrical bar becomes larger, it's value becomes opposite.