Daikichiro Mori

Strength of Cylindrical Shells with Cut-Out

The state of stresses in the vicinity of a square hole with rounded corners, including a circular hole as a special case, in a cylindrical shell subjected to axial load is analyzed. The analysis is carried out by two methods, that is, by the theory of shallow shell and the finite element method. The solutions of the Donnelltype equations with singular points at the centers of curvature of rounded corners and some other points, are superposed and the collocation technique is applied to satisfy the boundary conditions. The inflences of the curvature parameter β and the curvatures of the rounded corners of square holes on the state of stresses, especially stress concentrations, are investigated systematically. Several models are analyzed by the finite element method with flat triangular elements and the results are in good agreement with those of the former method except for cases of larger hole.

On the Influence of the Rigidity of Frame upon the Natural Vibration of a Car.

Abstract With the decrease of flexural stiffness of the frame of a car, the natural frequencies of pitching and bouncing motion decrease, the reduction percentage being proportional to k=kl3/EI.Influences of torsional stiffness of the frame upon the torsional vibration of a car are also discussed.

On the Application of Galerkin's Method

Abstract In the application of Galerkins method, the assumed function is usually taken in the form of a series of function of which every term satisfies the end condions. But this sort of choice is not always necessary. In this paper, severl vibration problems of bars are solved with enough accuracy by Galerkins method, using a series which satisfies the end condtions only as a whole.