On the derivation of boundary conditions for plate theory

1963 ◽  
Vol 276 (1365) ◽  
pp. 178-186 ◽  
Keyword(s):  
Differential Equations ◽  
Boundary Conditions ◽  
Elasticity Theory ◽  
Variational Formulation ◽  
Plate Theory ◽  
Three Dimensional ◽  
Interior Solution ◽  
Edge Zone ◽  
Joint Consideration ◽  
Three Dimensional Elasticity

Previous work on the derivation of plate theory by parametric expansions in three-dim ensional elasticity includes expansion of the interior solution (Goodier 1938) and simultaneous expansions of interior and edge-zone solutions (Friedrichs 1950; Friedrichs & Dressier 1961). The work of Goodier is concerned with the derivation of two-dim ensional differential equations while the work of Friedrichs & Dressier is concerned with the derivation of differential equations as well as boundary conditions, through the joint consideration of interior and edge-zone expansions. The principal object of the present paper is the derivation of boundary conditions for the successive terms of the interior solution expansion, without consideration of the edge-zone solution expansion. The method of derivation makes use of a variational formulation of three-dimensional elasticity theory.

On Shear Correction Factor in Vibration of Annular Sector Plates

2010 ◽  
Author(s):  
F. Hejripour ◽  
A. R. Saidi ◽  
S. H. Mirtalaie
Keyword(s):  
Boundary Conditions ◽  
Elasticity Theory ◽  
Correction Factor ◽  
Three Dimensional ◽  
Mode Shapes ◽  
Correction Factors ◽  
Asymmetric Mode ◽  
Shear Correction Factor ◽  
Annular Sector ◽  
Three Dimensional Elasticity

In the present study, the shear correction factors are obtained for annular sector plates using Differential Quadrature (DQ) Method. Based on the three-dimensional elasticity theory, the governing equations of motion for an annular sector plate are obtained. These equations together with the boundary conditions are discretized by employing DQ method. Following DQ procedure an eigenvalue problem is obtained that represents the natural frequencies and mode shapes of the plate. This procedure is also investigated for the analysis of the annular sector plates based on FSDT. The frequency of the first asymmetric mode of thickness direction for various shear correction factors are compared with the results of the three-dimensional elasticity theory. Therefore, the appropriate shear correction factor can be found. Some shear correction factors are obtained for various boundary conditions. It is shown that the value of the shear correction factor depends on the plate geometry and the boundary conditions.

scholarly journals Three-Dimensional Vibration Analysis of Rectangular Thick Plates on Pasternak Foundation with Arbitrary Boundary Conditions

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Huimin Liu ◽  
Fanming Liu ◽  
Xin Jing ◽  
Zhenpeng Wang ◽  
Linlin Xia
Keyword(s):  
Boundary Conditions ◽  
Admissible Function ◽  
Three Dimensional ◽  
Future Research ◽  
Pasternak Foundation ◽  
Arbitrary Boundary ◽  
Thick Plates ◽  
Arbitrary Boundary Conditions ◽  
Ritz Procedure ◽  
Three Dimensional Elasticity

This paper presents the first known vibration characteristic of rectangular thick plates on Pasternak foundation with arbitrary boundary conditions on the basis of the three-dimensional elasticity theory. The arbitrary boundary conditions are obtained by laying out three types of linear springs on all edges. The modified Fourier series are chosen as the basis functions of the admissible function of the thick plates to eliminate all the relevant discontinuities of the displacements and their derivatives at the edges. The exact solution is obtained based on the Rayleigh–Ritz procedure by the energy functions of the thick plate. The excellent accuracy and reliability of current solutions are demonstrated by numerical examples and comparisons with the results available in the literature. In addition, the influence of the foundation coefficients as well as the boundary restraint parameters is also analyzed, which can serve as the benchmark data for the future research technique.

scholarly journals Basic Solutions of Three Dimensional Elasticity

2021 ◽  
Vol 236 ◽  
pp. 05039
Author(s):  
Wx Zhang
Keyword(s):  
Boundary Conditions ◽  
Three Dimensional ◽  
Practical Calculation ◽  
Basic Solution ◽  
Final Solution ◽  
Theoretical Derivation ◽  
Basic Solutions ◽  
Special Solutions ◽  
Basic Equations ◽  
Three Dimensional Elasticity

Elastic calculation method is an important research content of computational mechanics. The problems of elasticity include basic equations and boundary conditions. Therefore, the final solution consists of the general solutions of the basic equations and the special solutions satisfying the boundary conditions. Numerical method is often used in practical calculation, but the analytical solution is also an important subject for researchers. In this paper, the basic solution of three-dimensional elastic materials is given by theoretical derivation.

Study of Stokes dynamical system in a thin domain with Fourier and Tresca boundary conditions

2019 ◽  
pp. 2150007 ◽  
Author(s):  
Y. Letoufa ◽  
H. Benseridi ◽  
M. Dilmi
Keyword(s):  
Boundary Conditions ◽  
Variational Formulation ◽  
Reynolds Equation ◽  
Mixed Boundary ◽  
Three Dimensional ◽  
Mixed Boundary Conditions ◽  
Dynamic Regime ◽  
Thin Domain ◽  
Problem Statement ◽  
Stokes Fluid

Asymptotic analysis of an incompressible Stokes fluid in a dynamic regime in a three-dimensional thin domain [Formula: see text] with mixed boundary conditions and Tresca friction law is studied in this paper. The problem statement and variational formulation of the problem are reformulated in a fixed domain. In which case, the estimates on velocity and pressure are proved. These estimates will be useful in order to give a specific Reynolds equation associated with variational inequalities and prove the uniqueness.

Lateral Buckling of Cantilevered Circular Arches Under Various End Moments

2020 ◽  
Vol 20 (07) ◽  
pp. 2071005
Author(s):  
Y. B. Yang ◽  
Y. Z. Liu
Keyword(s):  
Differential Equations ◽  
Boundary Conditions ◽  
Analytical Solutions ◽  
Analytical Approach ◽  
Three Dimensional ◽  
Curved Beams ◽  
Lateral Buckling ◽  
Circular Arch ◽  
Out Of Plane ◽  
The Moment

Lateral buckling of cantilevered circular arches under various end moments is studied using an analytical approach. Three types of conservative moments are considered, i.e. the quasi-tangential moments of the 1st and 2nd kinds, and the semi-tangential moment. The induced moments associated with each of the moment mechanisms undergoing three-dimensional rotations are included in the Newman boundary conditions. Using the differential equations available for the out-of-plane buckling of curved beams, the analytical solutions are derived for a cantilevered circular arch, which can be used as the benchmarks for calibration of other methods of analysis.

Three-Dimensional Plate Theory for Flexible Multibody Dynamics

2015 ◽  
Author(s):  
Shilei Han ◽  
Olivier A. Bauchau
Keyword(s):  
Plate Theory ◽  
Three Dimensional ◽  
Laminated Composite ◽  
Flexible Multibody Dynamics ◽  
Composite Plates ◽  
Complex Stress ◽  
Mindlin Plate ◽  
Stress States ◽  
Three Dimensional Elasticity ◽  
Material Line

In structural analysis, many components are approximated as plates. More often that not, classical plate theories, such as Kirchhoff or Reissner-Mindlin plate theories, form the basis of the analytical developments. The advantage of these approaches is that they leads to simple kinematic descriptions of the problem: the plate’s normal material line is assumed to remain straight and its displacement field is fully defined by three displacement and two rotation components. While such approach is capable of capturing the kinetic energy of the system accurately, it cannot represent the strain energy adequately. For instance, it is well known from three-dimensional elasticity theory that the normal material line will warp under load for laminated composite plates, leading to three-dimensional deformations that generate complex stress states. To overcome this problem, several high-order, refined plate theories have been proposed. While these approaches work well for some cases, they often lead to inefficient formulations because they introduce numerous additional variables. This paper presents a different approach to the problem: based on a finite element semi-discretization of the normal material line, plate equations are derived from three-dimensional elasticity using a rigorous dimensional reduction procedure.

A Mixed Method in Elasticity

1977 ◽  
Vol 44 (1) ◽  
pp. 51-56 ◽  
Author(s):  
N. S. V. Kameswara Rao ◽  
Y. C. Das
Keyword(s):  
Partial Differential Equations ◽  
Differential Equations ◽  
Boundary Conditions ◽  
Elastic Body ◽  
Mixed Method ◽  
Forced Vibration ◽  
Three Dimensional ◽  
Dynamic Problems ◽  
Partial Differential ◽  
Theory Of Plates

A mixed method for three-dimensional elasto-dynamic problems has been formulated which gives a complete choice in prescribing the boundary conditions in terms of either stresses, or displacements, or partly stresses and partly displacements. The general expressions for the responses of the elastic body have been derived in the form of transcendental partial differential equations of a set of initial functions, which can be evaluated in terms of the prescribed boundary conditions. The method so-formulated has been illustrated by applying it to the theory of plates. Only plates subjected to antisymmetric loads have been considered for illustration. Some examples of free and forced vibration of plates have been presented. Results are compared with solutions from existing theories.

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