FREE VIBRATION AND STABILITY OF THIN ELASTIC BEAMS SUBJECTED TO AXIAL FORCES

1996 ◽  
Vol 191 (5) ◽  
pp. 917-933 ◽  
Author(s):  
H. Matsunaga
Keyword(s):  
Free Vibration ◽  
Elastic Beams ◽  
Axial Forces

Investigation on the free vibration behavior of sandwich conical shells with reinforced cores

2021 ◽  
pp. 109963622110204
Author(s):  
Mehdi Zarei ◽  
Gholamhossien Rahimi ◽  
Davoud Shahgholian-Ghahfarokhi
Keyword(s):  
Free Vibration ◽  
Orientation Angle ◽  
Element Model ◽  
Filament Winding ◽  
Vertex Angle ◽  
Sandwich Shell ◽  
Cross Sectional ◽  
Conical Shells ◽  
Vibration Behavior ◽  
Axial Forces

The free vibration behavior of sandwich conical shells with reinforced cores is investigated in the present study using experimental, analytical, and numerical methods. A new effective smeared method is employed to superimpose the stiffness contribution of skins with those of the stiffener in order to achieve equivalent stiffness of the whole structure. The stiffeners are also considered as a beam to support shear forces and bending moments in addition to the axial forces. Using Donnell’s shell theory and Galerkin method, the natural frequencies of the sandwich shell are subsequently derived. To validate analytical results, experimental modal analysis (EMA) is further conducted on the conical sandwich shell. For this purpose, a method is designed for manufacturing specimens through the filament winding process. For more validation, a finite element model (FEM) is built. The results revealed that all the validations were in good agreement with each other. Based on these analyses, the influence of the cross-sectional area of the stiffeners, the semi-vertex angle of the cone, stiffener orientation angle, and the number of stiffeners are investigated as well. The results achieved are novel and can be thus employed as a benchmark for further studies.

Free vibration of layered magneto-electro-elastic beams by SS-DSC approach

2015 ◽  
Vol 125 ◽  
pp. 96-103 ◽  
Author(s):  
Libo Xin ◽  
Zhendong Hu
Keyword(s):  
Free Vibration ◽  
Elastic Beams

A vibration and buckling investigation of two-layered functionally graded cylindrical structures

2010 ◽  
Vol 224 (9) ◽  
pp. 1905-1913 ◽  
Author(s):  
H A Sepiani ◽  
A Rastgoo ◽  
H Karimipour ◽  
M H Naei
Keyword(s):  
Cylindrical Shell ◽  
Free Vibration ◽  
Transverse Shear ◽  
Shear Deformation Theory ◽  
Deformation Mode ◽  
Elastic Stability ◽  
Functionally Graded ◽  
Power Law Distribution ◽  
Axial Forces ◽  
Classical Shell Theory

This work investigates the free vibration and buckling of a two-layered cylindrical shell structure made of an elastic embedded functionally graded (FG) shell subjected to combined static and periodic axial forces. Such structures are widely used in chemical and nuclear reactors, space and aerial industries, and so on. Material properties of an FG cylindrical shell are considered to be temperature dependent and graded in the thickness direction according to a power-law distribution in terms of the volume fractions of the constituents. Theoretical formulations are presented based on two different methods of the first-order shear deformation theory considering the transverse shear strains and the rotary inertias and the classical shell theory. The results obtained show that the effect of transverse shear and rotary inertias on free vibration of an FG cylindrical shell is dependent on the material composition, deformation mode, and geometry parameters of the shells. It is concluded that the application of an outer elastic layer increases elastic stability.

FREE VIBRATION OF SEMI-RIGIDLY CONNECTED PILES EMBEDDED IN SOILS WITH DIFFERENT SUBGRADES

2008 ◽  
Vol 08 (02) ◽  
pp. 299-320 ◽  
Author(s):  
YUSUF YESILCE ◽  
HIKMET H. CATAL
Keyword(s):  
Free Vibration ◽  
Natural Frequency ◽  
Axial Force ◽  
Free Vibration Analysis ◽  
Subgrade Reaction ◽  
Rotational Spring ◽  
Winkler Model ◽  
Axial Forces ◽  
Rigid Connection ◽  
Pile Length

This paper is concerned with the free vibration analysis of Timoshenko piles partially embedded in elastic soil, semi-rigidly connected at the upper end, and subjected to an axial force. The pile is divided into three regions: the pile portion above the soil constitutes the first region, while the second and third regions are the pile portion that is embedded in two different layers of the soil type. The pile material is assumed to be linearly elastic and the axial force is constant along the pile length. The soil is idealized by the Winkler model and the semi-rigid connection of the pile is modeled by a rotational spring. The natural frequencies of the piles are calculated from the transfer matrix for different axial forces, rotational spring constants, subgrade reaction moduli and embedded lengths of the pile. The results indicate that the natural frequency of the pile decreases as the axial force increases. Further, the increase in the stiffness of the rotational spring at the upper end of the pile causes only a small increase in the natural frequency. Finally, both the pile length and the subgrade reaction of the soil influence significantly the natural frequency of the pile.

Free vibration analysis of non-prismatic beams under variable axial forces

2012 ◽  
Vol 43 (5) ◽  
pp. 561-582 ◽  
Author(s):  
H. Saffari ◽  
M. Mohammadnejad ◽  
M.H. Bagheripour
Keyword(s):  
Free Vibration ◽  
Vibration Analysis ◽  
Free Vibration Analysis ◽  
Axial Forces

The effects of shear deformation on the free vibration of elastic beams with general boundary conditions

2009 ◽  
Vol 224 (1) ◽  
pp. 71-84 ◽  
Author(s):  
J Li ◽  
H Hua
Keyword(s):  
Free Vibration ◽  
Boundary Conditions ◽  
Shear Deformation ◽  
Dynamic Stiffness ◽  
Beam Theory ◽  
Mode Shapes ◽  
Governing Equations ◽  
One Dimensional ◽  
Elastic Beams ◽  
Shear Deformable

Free vibration characteristics of shear deformable elastic beams subjected to different sets of boundary conditions are investigated. The analysis is based on a unified one-dimensional shear deformation beam theory. The governing equations of the elastic beams are obtained by means of Hamilton's principle. Four different boundary conditions are considered. The natural frequencies and mode shapes are obtained by applying the dynamic stiffness method, where the elements of the exact dynamic stiffness matrix are derived by using the analytical solutions of the governing equations of the beam in free vibration. The numerical results for the particular beams with different slenderness ratios are presented and compared with those available in the literature.

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