Local Flexibility of Cylindrical Shells and Pipes at the Support

1993 ◽  
Vol 115 (4) ◽  
pp. 359-363
Author(s):  
L. S. Ong
Keyword(s):  
Cylindrical Shell ◽  
Close Agreement ◽  
Shell Theory ◽  
Theoretical Data ◽  
Parametric Equation ◽  
Local Flexibility ◽  
Support Force ◽  
Geometric Variables ◽  
Applied Displacement

This article presents a parametric study for the determination of the flexibility and stiffness of a cylindrical shell at its support location. The parametric equation incorporates the geometric variables of both cylindrical shell and support; namely, the shell radius, thickness, and length, and the support width and embracing angle. A mathematical model has been devised to provide the theoretical data of flexibilities for establishing the parametric equation. The model is based on a contact stress formulation and uses a cylindrical shell theory. The validity and accuracy of the proposed parametric equation has been checked against available experimental results obtained from literature. There is close agreement between the two. The present study and results should be useful to designers who wish to determine the induced support force (or displacement) due to applied displacement (or force) at the support.

scholarly journals Standardization of proton induced X-ray emission for analysis of trace elements in thick samples

2019 ◽  
Vol 97 (8) ◽  
pp. 875-879
Author(s):  
Johar Zeb ◽  
Shad Ali ◽  
Muhammad Haneef ◽  
Azhar Muhammad Naeem ◽  
Jehan Akbar
Keyword(s):  
Experimental Data ◽  
Trace Elements ◽  
Close Agreement ◽  
Theoretical Data ◽  
Standard Reference Materials ◽  
Standard Samples ◽  
X Ray ◽  
Elemental Concentrations ◽  
Pelletron Accelerator

This paper presents the standardization of proton induced X-ray emission (PIXE) technique for the analysis of trace elements in thick, standard samples. Three standard reference materials, titanium, copper, and iron base alloys, were used for the study due to their availability. The proton beam was accelerated up to 2.57 MeV energy by 5UDH-II tandem Pelletron accelerator, and samples were irradiated at different geometries and durations. Spectra were acquired using a multi-channel spectrum analyzer, and spectra analyses were done using GUPIXWIN software for determination of elemental concentrations of trace elements. The obtained experimental data were compared with theoretical data and results were found to be in close agreement.

The quantitative comparison of experimental and simulated diffraction contrast images

1995 ◽  
Vol 53 ◽  
pp. 102-103
Author(s):  
Stuart McKernan
Keyword(s):  
Image Processing ◽  
Personal Computer ◽  
Close Agreement ◽  
Quantitative Comparison ◽  
Image Simulation ◽  
Computing Power ◽  
Diffraction Contrast ◽  
Simulated Images ◽  
Made In

For many years the concept of quantitative diffraction contrast experiments might have consisted of the determination of dislocation Burgers vectors using a g.b = 0 criterion from several different 2-beam images. Since the advent of the personal computer revolution, the available computing power for performing image-processing and image-simulation calculations is enormous and ubiquitous. Several programs now exist to perform simulations of diffraction contrast images using various approximations. The most common approximations are the use of only 2-beams or a single systematic row to calculate the image contrast, or calculating the image using a column approximation. The increasing amount of literature showing comparisons of experimental and simulated images shows that it is possible to obtain very close agreement between the two images; although the choice of parameters used, and the assumptions made, in performing the calculation must be properly dealt with. The simulation of the images of defects in materials has, in many cases, therefore become a tractable problem.

Local loads on a toroidal shell

1992 ◽  
Vol 27 (2) ◽  
pp. 59-66 ◽  
Author(s):  
D Redekop ◽  
F Zhang
Keyword(s):  
Cylindrical Shell ◽  
Shell Theory ◽  
Elastic Shell ◽  
Toroidal Shell ◽  
Pipe Bend ◽  
Local Loads ◽  
Simply Supported ◽  
Linear Elastic ◽  
Wide Range ◽  
Theory Solution

In this study the effect of local loads applied on a sectorial toroidal shell (pipe bend) is considered. A linear elastic shell theory solution for local loads is first outlined. The solution corresponds to the case of a shell simply supported at the two ends. Detailed displacement and stress results are then given for a specific shell with loadings centred at three positions; the crown circles, the extrados, and the intrados. These results are compared with results for a corresponding cylindrical shell. The paper concludes with a table summarizing results for characteristic displacements and stresses in a number of shells, covering a wide range of geometric parameters.

Response of a Submerged Cylindrical Shell to an Axially Propagating Step Wave

1965 ◽  
Vol 32 (4) ◽  
pp. 788-792 ◽  
Author(s):  
M. J. Forrestal ◽  
G. Herrmann
Keyword(s):  
Cylindrical Shell ◽  
Steady State ◽  
Wave Front ◽  
Transverse Shear ◽  
Shell Theory ◽  
Steady State Solution ◽  
State Solution ◽  
Rotatory Inertia ◽  
Shear Deformations ◽  
Axial Coordinate

An infinitely long, circular, cylindrical shell is submerged in an acoustic medium and subjected to a plane, axially propagating step wave. The fluid-shell interaction is approximated by neglecting fluid motions in the axial direction, thereby assuming that cylindrical waves radiate away from the shell independently of the axial coordinate. Rotatory inertia and transverse shear deformations are included in the shell equations of motion, and a steady-state solution is obtained by combining the independent variables, time and the axial coordinate, through a transformation that measures the shell response from the advancing wave front. Results from the steady-state solution for the case of steel shells submerged in water are presented using both the Timoshenko-type shell theory and the bending shell theory. It is shown that previous solutions, which assumed plane waves radiated away from the vibrating shell, overestimated the dumping effect of the fluid, and that the inclusion of transverse shear deformations and rotatory inertia have an effect on the response ahead of the wave front.

scholarly journals Isotherms of hydrogen, carbon monoxide and their mixtures

1931 ◽  
Vol 134 (824) ◽  
pp. 502-512 ◽  
Keyword(s):  
Carbon Monoxide ◽  
Pressure Range ◽  
Close Agreement ◽  
Gas Mixtures ◽  
Industrial Processes ◽  
Gaseous Mixtures ◽  
Previous Communication ◽  
New Apparatus ◽  
Temperature Ranges

In a previous communication from these laboratories by G. A. Scott an account was given of the determination of the isotherms of hydrogen, carbon monoxide and mixtures of the two in the molecular proportion 2 : 1, 1 : 1 and 1 : 2 over a pressure range up to 170 atmospheres and at a temperature of 25° C. Since the completion of that investigation new apparatus has been installed so that the pressure and temperature ranges might be extended; and in this paper are embodied the results of further determinations carried out at both 0° C. and 25° C. and over a pressure range extending up to 600 atmospheres. In pursuing this investigation further it is our endeavour to furnish information in regard to the gaseous mixtures in question over the pressure and temperature ranges now commonly used in industrial processes. The Isotherms of the Single Gases . A repetition in our new apparatus of the determinations previously made by Scott both for the single gases and gas mixtures at 25° C. and at pressures up to 170 atmospheres showed his figures to be in close agreement with our own, the variations never exceeding 0·1 per cent.

Determination of effective properties of granite rock: A numerical investigation

MRS Advances ◽  
2018 ◽  
Vol 3 (37) ◽  
pp. 2159-2168
Author(s):  
Rehema Ndeda ◽  
S. E. M Sebusang ◽  
R. Marumo ◽  
Erich O. Ogur
Keyword(s):  
Elastic Properties ◽  
Close Agreement ◽  
Effective Properties ◽  
Volume Element ◽  
The Finite Element Method ◽  
Effective Elastic Properties ◽  
Spherical Inclusions ◽  
Periodic Microstructures ◽  
Crack Profile

ABSTRACTMacroscopic strength of the rock depends on the behavior of the micro constituents, that is, the minerals, pores and crack profile. It is important to determine the effect of these constituents on the overall behavior of the rock. This study seeks to estimate the effective elastic properties of granite using the finite element method. A representative volume element (RVE) of suitable size with spherical inclusions of different distribution is subjected to loading and the effective elastic properties determined. The results are compared to those obtained from analytical methods. The elastic properties are obtained in both the axial and transverse direction to account for anisotropy. It is observed that there is congruence in the results obtained both analytically and numerically. The method of periodic microstructures exhibits close agreement with the numerical results.

Stresses in a Spherical Shell With a Nonradial Nozzle

1967 ◽  
Vol 34 (2) ◽  
pp. 299-307 ◽  
Author(s):  
D. E. Johnson
Keyword(s):  
Cylindrical Shell ◽  
Boundary Conditions ◽  
Spherical Shell ◽  
Shell Theory ◽  
Analytical Investigation ◽  
Type Method ◽  
Cylindrical Nozzle ◽  
Pass Through ◽  
External Forces ◽  
Radial Nozzle

An analytical investigation is made of the stresses due to external forces and moments acting on an elastic nonradial circular cylindrical nozzle attached to a spherical shell. The nozzle (a cylindrical shell) is nonradial in the sense that its axis is inclined and does not pass through the center of the sphere. Results are obtained by combining solutions from shell theory by a Galerkin-type method so as to satisfy boundary conditions at the intersection of the two shells. It is found that, as the nozzle inclination increases, the stresses change gradually from those previously given by Bijlaard for the radial nozzle.

scholarly journals A Semi-Analytical Solution for Elastic Analysis of Rotating Thick Cylindrical Shells with Variable Thickness Using Disk Form Multilayers

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Mohammad Zamani Nejad ◽  
Mehdi Jabbari ◽  
Mehdi Ghannad
Keyword(s):  
Cylindrical Shell ◽  
Analytical Solution ◽  
Differential Equations ◽  
Variable Thickness ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
First Order ◽  
Thick Cylinder ◽  
Good Agreement

Using disk form multilayers, a semi-analytical solution has been derived for determination of displacements and stresses in a rotating cylindrical shell with variable thickness under uniform pressure. The thick cylinder is divided into disk form layers form with their thickness corresponding to the thickness of the cylinder. Due to the existence of shear stress in the thick cylindrical shell with variable thickness, the equations governing disk layers are obtained based on first-order shear deformation theory (FSDT). These equations are in the form of a set of general differential equations. Given that the cylinder is divided intondisks,nsets of differential equations are obtained. The solution of this set of equations, applying the boundary conditions and continuity conditions between the layers, yields displacements and stresses. A numerical solution using finite element method (FEM) is also presented and good agreement was found.

High Temperature Guinier X-Ray Diffractometry for Thermal Expansion Measurements in the Hexagonal form of Cordierite ((2MgO•2Al2O3•5SiO2)

1983 ◽  
Vol 27 ◽  
pp. 397-404
Author(s):  
J. S. Pressnall ◽  
J. J. Fitzpatrick ◽  
Paul Predecki
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Close Agreement ◽  
Accurate Determination ◽  
Critical Test ◽  
Lattice Thermal Expansion ◽  
X Ray ◽  
Hexagonal Form ◽  
Computer Controlled

AbstractA computer-controlled high temperature Guinier diffractometer system for accurate determination of lattice thermal expansion is described. A critical test of the system using α-Al2O3 (0.3μ polishing alumina) showed close agreement with the single crystal expansion data of Wachtman et al. Lattice thermal expansion of cordierite doped with the following dopants: Ge+4, P+5, Zn+2, Li+1 and Ca+2 was investigated. Of these the Li+1 at the 5% level (5% of Si+4 replaced by Li+1 + Al+3) produced the largest decrease in mean lattice expansion.

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