scholarly journals Analytic bending solutions of free rectangular thin plates resting on elastic foundations by a new symplectic superposition method

Author(s):  
Rui Li ◽  
Yang Zhong ◽  
Ming Li

Analytic bending solutions of free rectangular thin plates resting on elastic foundations, based on the Winkler model, are obtained by a new symplectic superposition method. The proposed method offers a rational elegant approach to solve the problem analytically, which was believed to be difficult to attain. By way of a rigorous but simple derivation, the governing differential equations for rectangular thin plates on elastic foundations are transferred into Hamilton canonical equations. The symplectic geometry method is then introduced to obtain analytic solutions of the plates with all edges slidingly supported, followed by the application of superposition, which yields the resultant solutions of the plates with all edges free on elastic foundations. The proposed method is capable of solving plates on elastic foundations with any other combinations of boundary conditions. Comprehensive numerical results validate the solutions by comparison with those obtained by the finite element method.

2016 ◽  
Vol 165 (2) ◽  
pp. 3-8
Author(s):  
Rafał GRZEJDA

The paper presents modeling and calculations of multi-bolted connections at the assembly stage on an example of the engine cylinder head-block connection. The physical model of the connection was introduced as a combination of three subsystems: the set of bolts, the joined element and the contact layer between the joined element and the rigid support. The finite element method (FEM) was used for the modeling. Bolts were replaced with hybrid elements. The joined element was modeled with spatial finite elements. The Winkler model of the contact layer has been taken into consideration. The truth of the theorem has been examined, according to which non-linearity of the contact layer has a negligible impact on the final values of the bolt forces in the case of sequential preloading of the multi-bolted connection. The results of the calculations of a selected multi-bolted connection have been compared with the experimental results.


2010 ◽  
Author(s):  
G. K. Er ◽  
V. P. Iu ◽  
X. L. Liu ◽  
Jane W. Z. Lu ◽  
Andrew Y. T. Leung ◽  
...  

Author(s):  
J. Molina-Villegas ◽  
J. Ortega ◽  
A. Toro

Beams on elastic foundation are basic elements within structural analysis, which are used to model foundation beams, foundation piles, retaining walls, and more complex structures that include some of these elements. For their analysis, the finite element method is usually used [1], which produces an approximate solution of the problem; and the Green's function stiffness method [2], which produces an exact solution. This article presents a methodology 100% based on the use of Green function's (response to a unit point force), to obtain the exact response of beams on elastic foundation. The main advantage of this formulation is its computational low cost compared to the aforementioned alternatives, and even for a large number of problems, it can be expressed only by means of sums and integrals, which can be easily performed numerically. Also, a great variety of Green function's for finite and infinite beams on elastic foundations with different boundary conditions are also presented, as well as some examples with the implementation of the proposed methodology.


1986 ◽  
Vol 8 (2) ◽  
pp. 21-26
Author(s):  
Nguyen Ngoc Ve

Numerical simula1ion of complex special frame systems subjected to static load dynamic load and base acceleration is formulated. A finite element model is applied therein the, complex nodes and the foundation influence are considered. Equations of motion are soviet afterontively by step-by-step direct integration and mode superposition method. A number of illustrated  example are computed by the numerical superpose FRADYN), which can be used directly in the field of staeciural design.


2020 ◽  
pp. 107754632096782
Author(s):  
Xin Su ◽  
Eburilitu Bai

The free vibration of orthotropic rectangular thin plates with four free edges on two-parameter elastic foundations is studied by the symplectic superposition method. Firstly, by analyzing the boundary conditions, the original vibration problem is converted into two sub-vibration problems of the plates slidingly clamped at two opposite edges. Based on slidingly clamped at two opposite edges, the fundamental solutions of these two sub-vibration problems are respectively derived by the separation variable method of the corresponding Hamiltonian system, and then the symplectic superposition solution of the original vibration problem is obtained by superimposing the fundamental solutions of the two sub-problems. Finally, the symplectic superposition solution obtained in this study is verified by calculating the frequencies and mode functions of several concrete rectangular thin plates with four free edges.


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