Tsuneo Tsuiji’s research while affiliated with Nagasaki University and other places

Using the principle of virtual work and the Rayleigh–Ritz method with two dimensional algebraic polynomial displacement functions, the governing equation of vibration for a laminated cylindrical thin panel with twist and curvature is presented. The practicability and effectiveness of the method is verified by comparing the numerical results with those obtained by other researchers using experimental and other numerical methods. The effects of twist, curvature, characteristics of material, the number of layers, stacking sequence and fiber orientation on vibration frequency parameters of a laminated cylindrical thin panel with twist and curvature are studied, and some vibration mode shapes are also plotted to explain the variations of the vibration caused by them.

Blades are idealized as twisted cylindrical thin panels and the free vibrations of rotating blades are studied in this paper. First the steady deformation due to rotation is studied by using the principle of virtual work for deformation, then considering the initial deformations and the initial stress resultants, the vibration of the panel is analyzed by using the principle of virtual work for free vibration. The numerical procedure for analyzing the free vibrations of rotating twisted cylindrical thin panels is presented by the Rayleigh–Ritz method. The solutions are shown in non-dimensional frequency parameters and compared with the previous results. Finally, the effects of twist angle, center angle, setting angle, rotating speed and radius of rotating disc on the vibrations are investigated.

A numerical method for analyzing free vibrations of twisted thin conical shell panels is presented based on the Rayleight-Ritz procedure. To this end, exact strain-displacement relationships are derived by employing the thin shell theory and the principle of virtual work for free vibrations is formulated. Algebraic polynomials are used as assumed displacement functions in the analysis. Frequency parameters are analyzed for typical conical shell panels and effects of variation of the curvature of the shell and of pretwist on them are discussed. Resonance frequencies and modes of vibration obtained experimentally are compared with analytical ones. The agreement between them is found to be quite good.

A turbomachinery blade is treated as a cylindrical thin panel with curvature and twist. The non-linear strain–displacement relations of the model are derived based on the general thin shell theory, and a numerical method for analysing the free vibrations of curved and twisted cylindrical thin panels is presented by means of the principle of virtual work for the free vibration using the Rayleigh–Ritz method, assuming two dimensional polynomial functions as displacement functions. It is shown that the method is effective in solving free vibration problems for cylindrical thin panels with curvature and twist by comparing the numerical results with previous results. The effects of curvature and twist on the frequency parameters and mode shapes are also discussed.

Frequency parameters and modes of vibration are computed for thin laminated composite twisted cylindrical panels using the Rayleigh-Ritz method. Assumed displacement functions are taken to be algebraic polynomials. Comparison of frequency parameters obtained with avairable results in the literature shows that the method presented is effective for analyzing the vibration of thin laminated composite cylindrical panels. Effects of fiber orientation, sequence of laminate and initial twisted angle on the frequency parameters and modes of vibration are investigated.

A numerical method for analyzing free vibrations of composite laminated twisted cantilever thin plates is presented. The proposed method is based on the Rayleigh-Ritz procedure using algebraic polynomials as assumed displacement functions. The frequency parameters obtained are compared with previous theoretical results. Free vibrations of three-layer laminated (θ/-θ/θ) and four-layer laminated (θ/-θ/θ/-θ) plates are studied and the effect of fiber orientation and twist angle on the vibration characteristics of the plates is investigated.

Free vibrations of rotating cantilevered thin twisted plates are investigated. First, the exact strain-displacement relationships in large deflections of thin twisted plates are derived and the principle of virtual work for free vibrations of rotating cantilevered thin twisted plates is formulated. Then, a numerical procedure based on the Rayleigh-Ritz method is proposed using algebraic polynomials as assumed displacement functions. The results of the present analysis are compared with those obtained using the finite-element method to verify the usefulness of derived equations. Finally, effects of rotation, setting angle and setting length on frequency parameters are studied for typical thin twisted plates.

Free vibrations of twisted cantilevered thin plates having thickness varying in two directions are investigated analytically and experimentally in this study. A numerical procedure based on the Rayleigh-Ritz method is presented using algebraic polynomials as displacement functions. To demonstrate the procedure, nondimensional frequency parameters and mode shapes are analyzed for typical twisted plates. The convergence of frequency parameters is studied and effects of plate thickness variation on vibrating characteristics are discussed. Experimental tests are carried out for three kinds of aluminum specimens. On the basis of comparison between experimentally obtained resonance frequencies and mode shapes and those obtained from the analysis, it appears that the numerical procedure proposed in the present study is useful for analyzing the free vibrations of twisted thin plates with variable thickness

Fundamental equations governing free vibrations of curved and twisted thin plates, which are blade models of the advanced turboprop, are presented in this paper. First, exact strain displacement relationships for curved and twisted thin plates are derived based on the thin shell theory. Then, the principle of virtual work of free vibrations is formulated, which is the fundamental equation for establishing numerical procedures to analyze the vibration of the curved and twisted plate, such as the Rayleigh-Ritz method and the finite-element procedure. Since the equations are derived on the basis of shell theory, they are utilized for plates having large initial twist.

Free vibrations of curved and twisted cantilevered thin plates are investigated analytically and experimentally. A numerical method based on the Rayleigh-Ritz procedure is presented using algebraic polynomials as displacement functions and an approximate integration, dividing the plate into elements. Convergency studies of nondimensional frequency parameters are made with increase of the number of elements dividing the plate and of terms in the assumed functions. Then, effects of initial twist and curvature on vibrating characteristics are discussed for typical curved and twisted cantilevered plates. Finally, experimental tests are carried out and resonance frequencies and mode shapes obtained are compared with analytical results.