Free Vibration of a Fluid Loaded Ring-Stiffened Conical Shell With Variable Thickness

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
Ming Liu ◽  
Jun Liu ◽  
Yuansheng Cheng
Keyword(s):  
Free Vibration ◽  
Variable Thickness ◽  
Conical Shell ◽  
Shell Thickness ◽  
Low Frequency ◽  
Element Model ◽  
Governing Equations ◽  
Equivalent Method ◽  
The Finite Element Model ◽  
Good Agreement

An analytical method is presented for the free vibration of a fluid loaded (submerged) ring-stiffened conical shell with variable thickness in the low frequency range. Based on the Flügge theory and equivalent method of ring-stiffeners, the governing equations of vibration of a ring-stiffened conical shell are developed in the form of a coupled set of the first order differential equations. Fluid loading is taken into account by dividing the shell into narrow strips which are considered to be locally cylindrical. Analytical solutions are presented by using the transfer matrix method, which is suitable for structures broken into a sequence of subsystems that interact only with adjacent subsystems. By comparing the results from the present method and the finite element model, good agreement are obtained. The effects of the spacing of the stiffeners, the shell thickness, the shell thickness ratio, the ring's height, and the boundary conditions on the natural frequencies of the fluid loaded ring-stiffened conical shell with variable thickness are discussed.

scholarly journals Linear Vibration Analysis of Shells Using a Seven-Parameter Spectral/hp Finite Element Model

2020 ◽  
Vol 10 (15) ◽  
pp. 5102
Author(s):  
Carlos Valencia Murillo ◽  
Miguel Gutierrez Rivera ◽  
Junuthula N. Reddy
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Variable Thickness ◽  
Equations Of Motion ◽  
Shear Deformation Theory ◽  
Element Model ◽  
Linear Elastic ◽  
Commercial Code ◽  
The Finite Element Model ◽  
Hp Finite Element

In this paper, a seven-parameter spectral/hp finite element model to obtain natural frequencies in shell type structures is presented. This model accounts for constant and variable thickness of shell structures. The finite element model is based on a Higher-order Shear Deformation Theory, and the equations of motion are obtained by means of Hamilton’s principle. Analysis is performed for isotropic linear elastic shells. A validation of the formulation is made by comparing the present results with those reported in the literature and with simulations in the commercial code ANSYS. Finally, results for shell like structures with variable thickness are presented, and their behavior for different ratios r/h and L/r is studied.

The Effects of Geometrical Factors on the Step-Up Ratio in Piezoelectric Transformer

2007 ◽  
Vol 539-543 ◽  
pp. 3319-3325
Author(s):  
Man Soon Yoon ◽  
T.S. Yoon ◽  
J.R. Kim ◽  
Y.G. Choi ◽  
Soon Chul Ur
Keyword(s):  
Element Model ◽  
Vibration Modes ◽  
Electromechanical Properties ◽  
Piezoelectric Transformer ◽  
Voltage Step ◽  
3 Dimensional ◽  
Geometrical Factors ◽  
The Finite Element Model ◽  
Very High ◽  
Good Agreement

The electromechanical properties of a newly proposed 3-dimensional piezoelectric transformer have been investigated. Especially, the effects of 3-dimensional geometry on the maximum tip displacement were carefully investigated. As a result, it was found that the maximum strain of the 3-dimensional piezoelectric device was significantly enhanced up to 4.5 times higher than that of a disk shape device. This data were in good agreement with the finite element model analysis of strains and vibration modes. Moreover, a very high voltage step-up ratio of 290 (10 times higher than the Rosen type), sustaining efficiency more than 96%, were achieved.

Vibration Analysis of Reissner-Mindlin Plates Using Quadrilateral Heterosis Element

2010 ◽  
Vol 163-167 ◽  
pp. 1793-1796
Author(s):  
Zhong Liang Ru ◽  
Hong Bo Zhao ◽  
Chuan Rui Zhu
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Mass Matrix ◽  
Element Model ◽  
Mindlin Plate ◽  
Integration Scheme ◽  
Transverse Shear Locking ◽  
Locking Phenomena ◽  
Selective Reduced Integration ◽  
The Finite Element Model

The free vibration of the eigenfrequencies and models of a rectangular p1ate with simply supported comp1eted clamped supported were calculated by finite element method using the quadrilateral heterosis element. Firstly, the basic Governing equations of Reissner-Mindlin plate for elastodynamics was introduced, And then the finite element model of the plate vibration was established, nine nodes heterosis element was adopted, the stiffness matrix and mass matrix were obtained. Selective-reduced integration scheme was carried out to eliminatethe curvature thickness and the transverse shear locking phenomena in the plate bending. Numerical experiments of plate free vibration using heterosis element with quadrilateral linear shape functions for the displacements was studied, eight models ware obtained which were closely to the closed solutions, the results show that the method successfully yields a stabilized element.

Displacement Properties of Newly Developed 3-Dimensional Piezoelectric Actuator at Various AC Frequencies

2007 ◽  
Vol 534-536 ◽  
pp. 1441-1444 ◽  
Author(s):  
Man Soon Yoon ◽  
Y.G. Choi ◽  
Soon Chul Ur
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Piezoelectric Actuator ◽  
Element Model ◽  
Vibration Modes ◽  
Maximum Strain ◽  
Electromechanical Properties ◽  
3 Dimensional ◽  
The Finite Element Model ◽  
Good Agreement

The electromechanical properties of a newly proposed 3-dimensional piezoelectric actuator have been investigated. Especially, the effects of 3-dimensional geometry on the maximum tip displacement were carefully investigated. As a result, it was found that the maximum strain of the 3-dimensional piezoelectric device was significantly enhanced up to 4.5 times higher than that of a disk shape device. This data was in good agreement with the finite element model analysis of strains and vibration modes. Moreover, the field -induced displacement stability of dome-shaped 3- dimensional piezoelectric actuator at various ac freguencies was superior to Rainbow actuator.

scholarly journals Finite Element Analysis of Thermoelastic Instability With Intermittent Contact

1999 ◽  
Vol 122 (1) ◽  
pp. 42-46 ◽  
Author(s):  
Hubert J. M. Geijselaers ◽  
Annette J. E. Koning
Keyword(s):  
Finite Element ◽  
Element Model ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Governing Equations ◽  
Amplitude Function ◽  
Element Analysis ◽  
Thermoelastic Instability ◽  
Intermittent Contact ◽  
The Finite Element Model

The equations that describe the development of corrugations on block braked wheel treads caused by thermoelastic instability are discretized using the finite element method. The perturbations of temperatures and distortions are described by an amplitude function, which is spatially fixed multiplied by a sinusoidal running wave term of fixed wavelength. The governing equations are such that the wave term cancels out. Only the amplitude functions are discretized in the finite element model. The intermittent nature of the contact is directly specified through the boundary conditions. Results are obtained for a simplified two-dimensional model of a train wheel. These results agree with analytical results. [S0742-4787(00)00701-3]

Study on Modal Analysis for Motorcycle Frame by CAE Method

2014 ◽  
Vol 496-500 ◽  
pp. 601-604
Author(s):  
Jing Wang ◽  
Yong Wang ◽  
Ying Hua Liao
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Experimental Method ◽  
Dynamic Properties ◽  
Element Model ◽  
Analytic Method ◽  
Motorcycle Frame ◽  
The Finite Element Model ◽  
Good Agreement

In this paper, the modal of motorcycle frame is analyzed by using the analytic method and experimental method. The results show that the dynamic properties of the finite element model are in good agreement with the experiment and the finite element model was reliable and accurate.

Dynamic Pull-In Instability of Initially Curved Microbeams

2009 ◽  
Author(s):  
M. Moghimi Zand ◽  
M. T. Ahmadian ◽  
B. Rashidian
Keyword(s):  
Finite Element ◽  
Finite Difference ◽  
Finite Element Model ◽  
Electrostatic Force ◽  
Time Discretization ◽  
Element Model ◽  
Governing Equations ◽  
The Finite Element Model

In this study, dynamic pull-in instability and snap-through buckling of initially curved microbeams are investigated. The microbeams are actuated by suddenly applied electrostatic force. A finite element model is developed to discretize the governing equations and Newmark time discretization is employed to solve the discretized equations. The static pull-in behavior is investigated to validate the model. The results of the finite element model are compared with finite difference solutions and their convergence is examined. In addition, the influence of different parameters on dynamic pull-in instability and snap-through buckling is explored.

Free vibration of a conical shell with variable thickness

1982 ◽  
Vol 82 (1) ◽  
pp. 83-94 ◽  
Author(s):  
T. Irie ◽  
G. Yamada ◽  
Y. Kaneko
Keyword(s):  
Free Vibration ◽  
Variable Thickness ◽  
Conical Shell

Comparison and Validation of Dynamics Simulation Models for a Structurally Flexible Manipulator

1998 ◽  
Vol 120 (3) ◽  
pp. 404-409 ◽  
Author(s):  
Jeff Stanway ◽  
Inna Sharf ◽  
Chris Damaren
Keyword(s):  
Simulation Models ◽  
Element Model ◽  
Experimental Results ◽  
Dynamics Simulation ◽  
Flexible Manipulator ◽  
Direct Drive ◽  
Inertial Nonlinearities ◽  
Dynamics Models ◽  
The Finite Element Model ◽  
Good Agreement

This paper presents a series of experimental results obtained with a 2-DOF flexible-link direct-drive manipulator. First, we conduct a frequency analysis by comparing experimental natural frequencies with those predicted by the finite element model. Then, the time responses from four dynamics models are compared with each other and with the experiment. It is demonstrated that higher order nonlinearities are less important for slow maneuvers by close agreement between all four simulation models. For fast maneuvers, the two simpler models fail to predict a physically meaningful response. Good agreement with experimental results is attained with a model which accounts for all inertial nonlinearities. It is also shown that inclusion of damping in the dynamics models has a significant impact on their performance, as well as improving the correlation with experimental data.

scholarly journals Nonlinear Vibration of the Blade with Variable Thickness

2020 ◽  
Vol 2020 ◽  
pp. 1-18 ◽  
Author(s):  
Xiaobo Jie ◽  
Wei Zhang ◽  
Jiajia Mao
Keyword(s):  
Variable Thickness ◽  
Conical Shell ◽  
Deformation Theory ◽  
Equations Of Motion ◽  
Shear Deformation Theory ◽  
Dynamic Responses ◽  
Nonlinear Ordinary Differential Equations ◽  
Nonlinear Relationship ◽  
Governing Equations ◽  
First Order

In this paper, the nonlinear dynamic responses of the blade with variable thickness are investigated by simulating it as a rotating pretwisted cantilever conical shell with variable thickness. The governing equations of motion are derived based on the von Kármán nonlinear relationship, Hamilton’s principle, and the first-order shear deformation theory. Galerkin’s method is employed to transform the partial differential governing equations of motion to a set of nonlinear ordinary differential equations. Then, some important numerical results are presented in terms of significant input parameters.

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