Katsuyoshi Suzuki

Axisymmetric vibrations of thick shells of revolution having meridionally varying curvature.

An exact method using power series expansions is presented for solving axisymmetric free vibration problems for thick shells of revolution having meridionally varying curvature. Based on the improved thick shell theory, the Lagrangian of the shells of revolution are obtained, and the equations of motion and the boundary conditions are derived from the stationary condition of the Lagrangian. The method is applied to thick shells of revolution having their generating curves of ellipse, cycloid, parabola, catenary and hyperbola. The results by the present method are compared with those by the thin shell theory and the effects of rotatory inertia and shear deformation upon the natural frequencies and the mode shapes are clarified.

Vibrations of rotating thin circular cylindrical shells having different boundary condition at both ends.

An exact method using power series expansions is presented for solving free vibrations of rotating thin circular cylindrical shells. Equations of motion, which are differential equations with variable coefficients, are solved exactly by power series expansions for shells having different boundary conditions at both ends. Frequencies, mode shapes, bending moments, etc., are presented for shells with clamped -free ends. And their variations with rotating angular velocity are also shown.

Analysis of vibrations of rotating thick circular cylindrical shells.

An exact method using power series expansions is presented for solving free vibrations of rotating thick circular cylindrical shells. Equations of motion, which are differential equations with variable coefficients, are derived from an improved thick shell theory, and they are solved exactly by power series expansions. Frequencies and mode shapes are presented for rotating circular cylindrical shells with both ends clamped showing their variations with rotating angular velocity. The effects of shear deformation and rotatory inertia upon frequencies are also clarified by comparing the results of thin shell theory with those of the present theory.

Vibrations or a Connecting System of Curved Bar : Out-of-plane

In this paper, we express the Lagrangian of out-of-plane vibrations of a uniform curved bar of which the center line is a plane curve by unknown boundary values, that is, displacements and slopes at boundary. And by using the Lagrangian, we show a method for analyzing rigorously out-of-plane vibrations of a system connecting uniform curved bars. As examples, we analyze the vibrations of a symmetric U-bar with built-in ends composed of an elliptic arc bar and straight bars and those of a catenary curved bar and straight bars and we obtain the natural frequencies and the mode shapes.