Finite Hollow Cylinder Research Articles

On the characteristics of bolted joints with tap bolts. The case where clamped parts are hollow cylinders with a full-face metallic gasket.

In designing bolted joints, it is important to know the contact stress and the force ratio (the ratio of an increment of the bolt axial force to an external load). Up to now, some investigations have been carried out on the characteristics of bolted joints with gaskets. However, the compressive spring constants Kcg of the bolted joint in which a clamped part is fastened to a base with a tap bolt including a gasket have not been studied. In the present paper, the characteristics of the bolted joint with a full-face metallic gasket are examined. Replacing a clamped part, a gasket and a base with finite hollow cylinders, respectively, the contact stress distribution, the force ratio and the compressive spring constants are analyzed using a three-dimensional theory of elasticity. In the experiments, the force ratio is measured and the contact stress is measured by an ultrasonic wave. Analytical results are in fairly good agreement with experimental results. In addition, a simple calculation method to obtain Kcg is proposed.

TRANSIENT THERMAL STRESSES DUE TO PERIODICALLY MOVING LINE HEAT SOURCE OF COMPOSITE HOLLOW CYLINDER

Abstract The transient thermal stress distribution of a finite composite hollow cylinder, which is heated by a periodically moving line source on its inner boundary and cooled convectively on the outer surface, is analyzed in this paper. The heat sources are assumed to be axisymmetric, moving along the axis of the hollow cylinder with constant velocity. To solve the temperature distribution of the hollow cylinder, the Laplace transform and eigenfunction expansion methods are used. The associated thermal stress distributions are then obtained by solving the thermoelastic displacement function and the Love function. Finally, a numerical scheme, the Fourier series technique, is utilized to calculate the inverse transform. The numerical results of the temperature and thermal stress distribution are presented, which demonstrate the effects of thermal conductivity ratio, shear modulus ratio, Biol number, and period of the moving heat source.

Axisymmetric elastic equilibrium of finite hollow cylinders with deep grooves

Axisymmetric elastic equilibrium of finite hollow cylinders with deep grooves

On 3-dimensional non-axisymmetrical deformation analyses for finite hollow circular cylinders

In this paper, 3-dimensional non-axisymmetrical deformation analyses for finite hollow circular cylinders have been carried out by Pickett's double series expansion method[1]. Through expanding the displacement potentials as the sum of fourier series and Fourier-Bessel series, we could express the coefficients of one series by those of another under certain boundary conditions. Thus, a set of linear algebraic equations were derived. Solving these equations, we could obtain the solutions of the problems. Numerical examples have been given to show that the method presented here is workable for practical applications.

Three-dimensional stress analysis of adhesive butt joints subjected to tensile loads. (The case where adherends are two hollow cylinders).

This paper deals with a three-dimensional stress analysis of adhesive butt joints subjected to tensile loads in order to contribute to an establishment of the design of joints. Similar adherends and an adhesive bond are replaced with finite hollow cylinders in the analysis. Stress distributions in adhesive joints are analyzed strictly by using the three-dimensional theory of elasticity. The effects of stiffness and thickness of the adhesive bonds on the normal and the shear stress distributions are shown by numerical computations. The analytical result is also compared with the result obtained by F.E.M. in order to verify the stress distributions in adhesive bonds. It is shown that they are in fairly good agreement.

On the Characteristics of a Bolted Joint with Tap Bolts : the case where a clamped part is a cover of a pressure vessel

This paper discussed on a distribution of contact stresses when the cover of a pressure vessel is fastened with tap bolts to a vessel. In the analysis, by replacing the cover and the vessel by a finite hollow cylinder the distribution of contact stresses is analyzed by three dimensional theory of elasticity. In addition, the force ratio, which is the ratio of an increment of a bolt axial force to a load when a pressure is applied, is analyzed by using three dimensional theory of elasticity and theory of beam on an elastic foundation. Moreover, the maximum stress caused in bolts when a pressure is applied, is also analyzed. Then, a method to estimate the pressure causing a separation of the interface and a leakage of fluid from the joint is proposed. For verification, experiments are carried out. Analytical results are in a fairly good agreement with experimental ones.

On the Characteristics of Bolted Joints with Gaskets : stress analysis of full face metallic flat gaskets interposed between pipe flanges

This paper deals with a contact stress distribution in bolted joints when a full face metallic flat gasket is interposed between two pipe flanges. Replacing a gasket and pipe flanges by finite hollow cylinders the contact stress distribution is analyzed using three-dimensional theory of elasticity. By numerical computations, effects of the thickness and the stiffness of gaskets on the contact stress distribution are shown. Next, the force ratio of bolted joints with gaskets, which is the ratio of an increment of bolt axial force to an internal pressure and the sealing performance are analyzed. With an application of the internal pressure, a bending moment is produced in bolts. The maximum stress produced in bolts taking this bending moment into consideration is also analyzed. For verification, experiments are performed. Analytical results are in a fairly good agreement with experimental one.

Contact Pressure Measurement by Means of Ultrasonic Waves : On a Bolted Joint with a Solid-metal Flat Gasket

A quantitative measurement of contact pressure by means of ultrasonic waves using a normal probe has been proposed to measure the contact pressure on a bolted joint with a solid-metal flat gasket. At first, in a proposed calibration method, the relation between mean contact pressure and sound pressure of reflected waves is obtained using the calibration blocks with various surface roughnesses and heights made of the same material as the bolted joint. Both sides of the laminated finite hollow cylinders are compressed under a locally uniform pressure, and the sound pressure of reflected waves is measured. From these relations, the contact pressure is obtained. The experimental results agree approximately with the theoretical ones. It is demonstrated that the gasket has an effect of preventing the leakage and the proposed ultrasonic method is practically useful.

Simple formula for the RCS of a finite hollow circular cylinder

A plain and simple, yet accurate, formula is obtained to calculate the backscattered radar cross-section (RCS) of a perfectly conducting, finite, hollow, circular cylinder with a closed termination. The reradiated field from the cavity region is evaluated via the Kirchhoff approximation and the reciprocity theorem. The scattering from the exterior surface is approximated by the geometrical theory of diffraction (GTD), in conjunction with the equivalent current (EC) concept. The solution neglects the multiple scattering between the open and closed ends of the cavity and can be easily applied to the electromagnetic scattering from a very large cavity.

Elastic behaviour of shrink-fitted forming die assemblies. Part I: Development of an analytical solution

The paper deals with the elastic behaviour of the die assemblies obtained by shrinking a thick walled ring onto a finite hollow right circular cylinder in general of different length. Displacements and stresses in the two components of the assembly are evaluated by using the theoretical general solution on the finite thick-walled hollow elastic right circular cylinder with an axially symmetrical load system in terms of Airy's stress function. Radial and axial displacement influence coefficient technique is used to solve the integral equations governing the two extreme frictionless and slipless contact modes at the mating surface.

Contact Stresses in Two Elastic Bodies : Elastic Bodies are Finite Hollow Cylinders

In this paper, the contact stress between two different finite hollow cylinders connected by a bolted joint is studied. The three dimensional theory of elasticity is used to analyse the contact stress and the deformation in laminated finite hollow cylinders whose both sides are compressed axisymmetrically under a local uniform pressure. By neglecting shearing stress on the contact surface, an exact solution satisfying the remaining boundary conditions is obtained. Numerical calculations are carried out for various rigidities and thicknesses of the finite hollow cylinders under various loading conditions. In order to examine the results of the theoretical analysis, the contact stress is measured experimentally by using pressure-sensitive pins attached to a finite hollow cylinder. It is confirmed that the theoretical results agree well with the experimental ones except at the vicinity of the loaded area.

Torsional wave propagation in a finite inhomogeneous cylindrical shell under time-dependent shearing stress

Torsional wave motion in a finite hollow cylinder of piezoelectric material of (622) crystal class, under a time-dependent mechanical boundary condition is investigated. The inhomogeneity is restricted to the variations of density and other physical constants of the medium as a certain power of the radial distance. The expressions for the displacement and the electric potential of the present solution are compared with those under time-dependent electric boundary condition. Numerical values of the roots of the frequency equation for β-quartz are presented.

The gravitational field inside a long hollow cylinder of finite length

The gravitational force inside a finite hollow cylinder has been calculated for the Newtonian potential and for a non-Newtonian potential, and the results of the experiments of Spero et at . (1980) and Long (1976) have been reinterpreted in terms of limits on departures from the Newtonian potential.

Contact Stresses in Two Elastic Bodies : In the Case of Elastic Bodies Being Finite Hollow Cylinders

Contact Stresses in Two Elastic Bodies : In the Case of Elastic Bodies Being Finite Hollow Cylinders

Dependence of forms of elasticity solutions on boundary conditions

The relationships between the forms of three-dimensional elastostatics solutions and the types of prescribed boundary conditions are developed using integral transform methods applied to a finite hollow circular cylinder. It is shown that closed-form and quasi-closed-form solutions are obtainable only for special combinations of boundary conditions and geometric proportions.

Quantifying solute distributions in the bioturbated zone of marine sediments by defining an average microenvironment

The bioturbated zone of marine sediments is a region having a complex, time-dependent geometry of diffusion and chemical reactions. It is possible to simplify this geometry by postulating an average sediment microenvironment and modelling it as representative of the sediment body as a whole. The microenvironment is assumed to correspond to a single, tube-dwelling animal together with its surrounding sediment and can be represented by a finite hollow cylinder. A transport-reaction model derived from this postulate produces good agreement between observed and predicted pore water profiles using realistic physical constants. The average vertical distributions of pore water solutes and their sediment-water fluxes are influenced by the presence of irrigated burrows to varying degrees depending on the kind of reactions governing their behavior. Pore water profiles of solutes, such as NH + 4, subject to zero order reaction rates are highly sensitive to the abundance and sizes of burrows while the net flux of the constituent across the sediment-water interface is not. In contrast, profiles of solutes such as Si that are subject to first order reaction rates are less sensitive to the presence of irrigated burrows but net fluxes are greatly affected. Average pore water concentrations, fluxes of solutes like Si and the apparent one-dimensional diffusion coefficients required to match vertical gradients with measured solute fluxes, are influenced by both the size and spacing of burrows. Because of the range of solute concentrations within the microenvironment at any given depth it is not strictly valid to make detailed solubility calculations on the basis of average pore water concentrations within the bioturbated zone.

Solution of a mixed boundary-value problem of elasticity theory for a finite hollow cylinder

Solution of a mixed boundary-value problem of elasticity theory for a finite hollow cylinder

Three Dimensional Analysis of a Finite Hollow Cylinder Subjected to Axiasymmetric Deformations

Three Dimensional Analysis of a Finite Hollow Cylinder Subjected to Axiasymmetric Deformations

Three Dimensional Analysis of a Finite Hollow Cylinder Subjected to Axi-Asymmetric Deformations

Three dimensional elastic analysis of a finite hollow cylinder is very important to a practical design of machine parts. A few kinds of problems on an infinite hollow cylinder subjected to axi-asymmetric loads has already been studied. But the problem of a finite cylinder subjected to axi-asymmetric loads has not yet been analyzed. In this paper, a double Fourier series solution on the analysis of a finite hollow cylinder subjected to axi-asymmetric loads has been obtained by introducing stress functions which are given as series forms. Numerical results for some boundary conditions are obtained by using a digital computer and effects of Poisson's ratio, the ratio of inner radius to outer radius, and so on are discussed.

A new approach to the thin scatterer problem using the hybrid equations

A new set of integral equations for electromagnetic scattering problems, the hybrid equations, is presented. The advantages of these equations for thin perfect conductors are discussed in comparison to the magnetic and electric field integral equations. Specific comparisons are made with the solution of the electric field integral equation for a finite hollow cylinder. It is demonstrated that the primary advantage of these equations is obtained by minimizing the coupling between component equations for the two surface currents.