scholarly journals ANALYTICAL MODEL OF A METASURFACE CONSISTING OF A REGULAR ARRAY OF SUB-WAVELENGTH CIRCULAR HOLES IN A METAL SHEET

2011 ◽  
Vol 18 ◽  
pp. 209-219 ◽  
Author(s):  
Davide Ramaccia ◽  
Filiberto Bilotti ◽  
Alessandro Toscano
Keyword(s):  
Analytical Model ◽  
Metal Sheet ◽  
Regular Array ◽  
Circular Holes ◽  
Sub Wavelength

scholarly journals Analytical Model of Connected Bi-Omega: Robust Particle for the Selective Power Transmission Through Sub-Wavelength Apertures

2014 ◽  
Vol 62 (4) ◽  
pp. 2093-2101 ◽  
Author(s):  
Davide Ramaccia ◽  
Luca Di Palma ◽  
Damla Ates ◽  
Ekmel Ozbay ◽  
Alessandro Toscano ◽  
...  
Keyword(s):  
Analytical Model ◽  
Power Transmission ◽  
Sub Wavelength

scholarly journals Determination of the Fundamental Frequency of Perforated Rectangular Plates: Concentrated Negative Mass Approach for the Perforation

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Kiran D. Mali ◽  
Pravin M. Singru
Keyword(s):  
Analytical Model ◽  
Perforated Plate ◽  
Rectangular Plates ◽  
Perforated Plates ◽  
Cosine Series ◽  
Circular Holes ◽  
Support Conditions ◽  
Mechanical Devices ◽  
The Galerkin Method

This paper is concerned with a vibration analysis of perforated rectangular plates with rectangular perforation pattern of circular holes. The study is particularly useful in the understanding of the vibration of sound absorbing screens, head plates, end covers, or supports for tube bundles typically including tube sheets and support plates used in the mechanical devices. An energy method is developed to obtain analytical frequencies of the perforated plates with clamped edge, support conditions. Perforated plate is considered as plate with uniformly distributed mass. Holes are considered as concentrated negative masses. The analytical procedure using the Galerkin method is adopted. The deflected surface of the plate is approximated by the cosine series which satisfies the boundary conditions. Finite element method (FEM) results have been used to illustrate the validity of the analytical model. The comparisons show that the analytical model predicts natural frequencies reasonably well for holes of small size.

Evaluation of Un-Cracking Delamination by Pseudo Crack Model (PCM) in FRMLs

2007 ◽  
Vol 345-346 ◽  
pp. 689-692
Author(s):  
Cheol Woong Kim ◽  
Dong Joon Oh ◽  
Ki Weon Kang ◽  
Young Ho Ko
Keyword(s):  
Crack Growth ◽  
Analytical Model ◽  
Consumption Rate ◽  
Crack Model ◽  
Al Alloy ◽  
Fracture Parameters ◽  
Fiber Bridging ◽  
Circular Holes ◽  
Fatigue Characteristics ◽  
The Relationship

If Fiber Reinforced Metal Laminates (FRMLs) were delaminated, the decrease of stiffness and fiber bridging effect would result in the sudden aggravation of fatigue characteristics. It was reported that the delamination of FRMLs resulted from the crack of Al alloy layers and that it depended on the crack growth. When FRMLs with circular holes was un-cracked but was delaminated, it was impossible to analyze them by conventional fracture parameters expressed as the function of cracks. Therefore, a new analytical model called Pseudo Crack Model (PCM) was suggested to compare the delaminations whether cracks were made or not. The relationship between the crack consumption rate (Ccrack) and the delamination consumption rate (Cdel) was discussed and it was also known that the effect of the Ccrack was larger than that of the Cdel.

scholarly journals On the buckling of an elastic holey column

2017 ◽  
Vol 473 (2207) ◽  
pp. 20170477 ◽  
Author(s):  
C. G. Johnson ◽  
U. Jain ◽  
A. L. Hazel ◽  
D. Pihler-Puzović ◽  
T. Mullin
Keyword(s):  
Critical Strain ◽  
Theoretical Study ◽  
Regular Array ◽  
Buckling Mode ◽  
Buckling Modes ◽  
Euler Buckling ◽  
Circular Holes ◽  
Regular Line ◽  
Slender Columns ◽  
Fitting Parameters

We report the results of a numerical and theoretical study of buckling in elastic columns containing a line of holes. Buckling is a common failure mode of elastic columns under compression, found over scales ranging from metres in buildings and aircraft to tens of nanometers in DNA. This failure usually occurs through lateral buckling, described for slender columns by Euler’s theory. When the column is perforated with a regular line of holes, a new buckling mode arises, in which adjacent holes collapse in orthogonal directions. In this paper, we firstly elucidate how this alternate hole buckling mode coexists and interacts with classical Euler buckling modes, using finite-element numerical calculations with bifurcation tracking. We show how the preferred buckling mode is selected by the geometry, and discuss the roles of localized (hole-scale) and global (column-scale) buckling. Secondly, we develop a novel predictive model for the buckling of columns perforated with large holes. This model is derived without arbitrary fitting parameters, and quantitatively predicts the critical strain for buckling. We extend the model to sheets perforated with a regular array of circular holes and use it to provide quantitative predictions of their buckling.

Theoretical Study of the Dynamic Effects Based on Work-Roll Model in Metal Sheet Rolling Process

2012 ◽  
Vol 538-541 ◽  
pp. 595-600
Author(s):  
Qiao Yi Wang ◽  
Yao Zhu ◽  
Rui Jin Gao ◽  
Yong Zhao
Keyword(s):  
Analytical Model ◽  
Dynamic Instability ◽  
Work Roll ◽  
Rolling Process ◽  
Metal Sheet ◽  
Backup Roll ◽  
Sheet Rolling ◽  
Linear Elastic ◽  
Nonlinear Analytical Model ◽  
Roll Bite

A new analytical model for the configuration of a four-high rolling mill stand is proposed in this article. Using the model, the dominant sources of stiffness in the fifth octave and the third octave models are identified. The assumptions made for the derivation of the model are that the work rolls are isotropic linear elastic, that there is no gap or separation between the work roll and the backup roll at all times. In addition, only the vertical interactions of the work roll and the roll-bite are considered. The nonlinear characteristics of this dynamic system are contributed from the contact area of the work roll and the backup roll. Analyses show that the natural frequency of the nonlinear analytical model matches the fifth octave rolling chatter, and the dominant parameters of the dynamic instability are characterized. The effects of inter-stand tensions, rolling speeds, friction between the work roll and the metal sheet roll-bite, and the thickness of the metal sheet on rolling chatter are discussed in the analysis of the dynamics of the rolling model.

Electron Optical Study of Surface Morphologies of Crystals

1980 ◽  
Vol 38 ◽  
pp. 376-377
Author(s):  
Sumio Iijima ◽  
Tung Hsu
Keyword(s):  
Thin Film ◽  
Optical Study ◽  
Regular Array ◽  
Surface Steps ◽  
Diffracted Waves ◽  
Image Position ◽  
Surface Morphologies

Suppose the thickness of a thin film of a crystal varies periodically like a regular array of surface steps, kinematical intensities of diffracted waves from this crystal are modulated by a shape transform,

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