Determination of the orthotropic plate parameters of stiffened plates and grillages in free vibration

1967 ◽  
Vol 17 (6) ◽  
pp. 422-438 ◽  
Author(s):  
K. T. Sundara Raja Iyengar ◽  
R. Narayana Iyengar
Keyword(s):  
Free Vibration ◽  
Orthotropic Plate ◽  
Stiffened Plates

Theoretical Determination of Rigidity Properties of Orthogonally Stiffened Plates

1956 ◽  
Vol 23 (1) ◽  
pp. 15-20
Author(s):  
N. J. Huffington
Keyword(s):  
Elastic Constants ◽  
Orthotropic Plate ◽  
Constant Thickness ◽  
Stiffened Plates ◽  
Geometrical Configuration ◽  
Orthotropic Plates ◽  
Theoretical Determination

Abstract The analysis of bending and buckling of orthogonally stiffened plates may be simplified by conceptually replacing the plate-stiffener combination by an “equivalent” homogeneous orthotropic plate of constant thickness. This procedure requires the determination of the four elastic rigidity constants which occur in the theory of thin orthotropic plates. Methods are presented whereby these quantities may be determined analytically in terms of the elastic constants and geometrical configuration of the component parts of the structure.

Finite element free vibration of eccentrically stiffened plates

1988 ◽  
Vol 30 (6) ◽  
pp. 1303-1317 ◽  
Author(s):  
Abhijit Mukherjee ◽  
Madhujit Mukhopadhyay
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Stiffened Plates ◽  
Element Free

Tables for Frequencies and Modes of Free Vibration of Infinitely Long Thin Cylindrical Shells

1954 ◽  
Vol 21 (2) ◽  
pp. 178-184
Author(s):  
M. L. Baron ◽  
H. H. Bleich
Keyword(s):  
Free Vibration ◽  
Poisson’S Ratio ◽  
Cylindrical Shells ◽  
Bending Stiffness ◽  
Poisson's Ratio ◽  
Underlying Theory ◽  
Half Wave ◽  
Quick Determination ◽  
Circumferential Waves

Abstract Tables are presented for the quick determination of the frequencies and shapes of modes of infinitely long thin cylindrical shells. To make the problem tractable, the shells are first treated as membranes without bending stiffness, and the bending effects are introduced subsequently as corrections. The underlying theory is based on the energy expressions for cylindrical shells. The tables cover the following range: lengths of longitudinal half wave L from 1 to 10 radii a; number n of circumferential waves from 0 to 6. The results apply for Poisson’s ratio ν = 0.30.

An Evaluation and Comparison of Models for Maximum Deflection of Stiffened Plates Using Finite Element Analysis

2007 ◽  
Vol 44 (04) ◽  
pp. 212-225
Author(s):  
Lior Banai ◽  
Omri Pedatzur
Keyword(s):  
Finite Element ◽  
Orthotropic Plate ◽  
Lateral Pressure ◽  
Stiffened Plates ◽  
Maximum Deflection ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Element Analysis ◽  
The Past ◽  
Different Types

Stiffened plates form the backbone of most of a ship's structure. Today, finite element (FE) models are used to analyze the behavior of such structural elements for different types of loads. In the past, when usage of computers and FE models were not used very much, analytical analysis methods were required. Two well-known methods have been developed for analyses of stiffened plates under lateral loading (uniform pressure), based on two different models, namely, the orthotropic plate model and the grillage model. Both models can give estimations for the maximum plate deflection under uniform lateral pressure. The objective of this paper is to present the two methods, evaluate and compare the methods using the finite element method, and finally implement the methods as a computer program for quick estimations of the maximum deflection of stiffened plates. The degree of accuracy of the two methods when compared to FE is discussed in some detail.

Large Amplitude Forced Vibration Analysis of Stiffened Plates under Harmonic Excitation

2012 ◽  
pp. 26-61
Author(s):  
Anirban Mitra ◽  
Prasanta Sahoo ◽  
Kashinath Saha
Keyword(s):  
Free Vibration ◽  
Forced Vibration ◽  
Large Amplitude ◽  
Vibration Analysis ◽  
Mathematical Formulation ◽  
Free Vibration Analysis ◽  
Harmonic Excitation ◽  
Stiffened Plates ◽  
Backbone Curve ◽  
Forced Vibration Analysis

Large amplitude forced vibration behaviour of stiffened plates under harmonic excitation is studied numerically incorporating the effect of geometric non-linearity. The forced vibration analysis is carried out in an indirect way in which the dynamic system is assumed to satisfy the force equilibrium condition at peak excitation amplitude. Large amplitude free vibration analysis of the same system is carried out separately to determine the backbone curves. The mathematical formulation is based on energy principles and the set of governing equations for both forced and free vibration problems derived using Hamilton’s principle. Appropriate sets of coordinate functions are formed by following the two dimensional Gram-Schmidt orthogonalization procedure to satisfy the corresponding boundary conditions of the plate. The problem is solved by employing an iterative direct substitution method with an appropriate relaxation technique and when the system becomes computationally stiff, Broyden’s method is used. The results are furnished as frequency response curves along with the backbone curve in the dimensionless amplitude-frequency plane. Three dimensional operational deflection shape (ODS) plots and contour plots are provided in a few cases.

scholarly journals Free vibration characteristics of stiffened plates

2018 ◽  
Vol 10 (2) ◽  
pp. 153-167 ◽  
Author(s):  
Amar N. Nayak ◽  
Laren Satpathy ◽  
Prasant K. Tripathy
Keyword(s):  
Free Vibration ◽  
Vibration Characteristics ◽  
Stiffened Plates

Free Vibration of Continuous Skin-Stringer Panels

1960 ◽  
Vol 27 (4) ◽  
pp. 669-676 ◽  
Author(s):  
Y. K. Lin
Keyword(s):  
Free Vibration ◽  
Boundary Conditions ◽  
Natural Frequencies ◽  
Normal Modes ◽  
Time Dependent ◽  
Experimental Measurements ◽  
Structural Configuration ◽  
Modes Of Vibration ◽  
Fuselage Skin

The determination of the natural frequencies and normal modes of vibration for continuous panels, representing more or less typical fuselage skin-panel construction for modern airplanes, is discussed in this paper. The time-dependent boundary conditions at the supporting stringers are considered. A numerical example is presented, and analytical results for a particular structural configuration agree favorably with available experimental measurements.

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