抄録
It is no easy task to get an analytical solution of the dynamic stress around a hole of whatever shape in a material. A report of studies is presented in this paper made of the dynamic stress in two materials with holes, one circular, and the other square, both caused by the propagation of pulsive cylindrical stress wave. The stress was analysed by a numerical technique which involved the fine difference approximation to the momentum equations. The main results obtained are as follows.
(1) Stress concentration factors on the surface of the circular hole obtained by this numerical analysis agree fairly well with the analysis worked by M. T. Jakub and C. C. Mow.
(2) The state of stress distribution around the circular hole changes with the ratio of λ/d, where λ is a wave length of the stress wave and d is a diameter of the hole. When the value of λ/d is greater than 2 or 3, the disturbance of the stress due to the existence of the hole becomes similar to that obtained under quasi-statical stress field. When the value of λ/d is smaller than 2 or 3, on the other hand, the stress wave reflects on the surface of the circular hole as if it reflected on a plane surface and the reflected waves from the surface of the hole had a dominant effect on the stress distribution.
