Showing papers on "Shell (structure) published in 1984"

Method of making a composite article including a body having a decorative metal plate attached thereto

Abstract: A method of manufacturing a composite article including a hollow body having a decorative metal plate attached thereto. The method includes the forming of a decorative metal plate and the attachment of the plate to a hollow body. The method can be best described by its application to the manufacture of a push button which involves the following: Forming a rectangular sheet of aluminum which sheet has at least one decorative brushed surface. Machining the brushed aluminum surface of the aluminum sheet in an annular pattern around the perimeter of the sheet to remove a uniform thickness of the aluminum thereby leaving a central rectangular island of brushed aluminum. The central rectangular island thus formed is surrounded on all sides by the machined surface which functions as an apron around the island. All of the machined surface apron on both long sides of the rectangular island is removed leaving tabs of apron extending from the opposite short ends of the rectangular island. The tabs are bent away from the brushed aluminum surface so that they extend at generally right angles to the brushed aluminum surface of the island. The metal plate thus formed is attached to the plastic shell by inserting the tabs into passages formed in one end of the plastic shell while positioning the island against the plastic shell. The tabs are crimped to lock the aluminum plate to the plastic shell to complete the push button.

Exact Solutions of Moderately Thick Laminated Shells

Abstract: An extension of the Sanders shell theory for doubly curved shells to a shear deformation theory of laminated shells is presented. The theory accounts for transverse shear strains and rotation about the normal to the shell midsurface. Exact solutions of the equations are presented for simply supported, doubly curved, cross‐ply laminated shells under sinusoidal, uniformly distributed, and concentrated point load at the center. Fundamental frequencies of cross‐ply laminated shells are also presented. The exact solutions presented herein for laminated composite shells should serve as bench mark solutions for future comparisons.

Extended model of the electron in general relativity

Abstract: A classical model of the spinning electron is proposed in which this particle is the source of the Kerr-Newman field. The electron is regarded as a charged rotating shell endowed with surface tension. It is the boundary where the exterior Kerr-Newman solution is matched to the interior flat spacetime metric. The shell is the surface of an oblate ellipsoid of revolution having a minor axis equal to the classical electron radius and a focal distance of the order of the corresponding Compton wavelength. This surface is undergoing rigid rotation with its equator at a velocity almost equal to the velocity of light. The arrangement of charges gives rise to a quadrupole electric moment, in addition to the magnetic dipole moment of the current distribution. The whole spacetime of this model is shown to be causally well behaved.

Multi-element thermocouple

Abstract: In a means for supporting an elongated heavy thermocouple assembly the weight of the assembly is carried by a rigid support at an intermediate point along its length instead of by a long lever arm exerting a substantial torque at the point of attachment to the reactor vessel shell as in the conventional design.

Night light assembly

Abstract: A night light assembly which plugs into and is supported by an electrical wall outlet whose orientation on the wall is either horizontal or vertical The assembly, when switched on, produces low-level illumination and at the same time exudes an aromatic vapor The assembly includes a reflector shell having housed therein a low-wattage bulb Attached to the open front of the shell is a frame adapted to accommodate a removable window cartridge having a transparent plate whose rear face is covered by a thin pad of light-permeable porous material impregnated with a volatile aromatic liquid The shell is vented, and as the air therein is heated and expanded by heat emanating from the bulb, a convection current is produced which flows across the pad to volatilize the liquid, thereby creating an aromatic vapor that is discharged through the vent Adherable to the front face of the window plate is a translucent sheet having a picture thereon of an object possessing a characteristic odor, the fragrance of the aromatic vapor being thematically related thereto The sheet is so adhered to the plate as to orient the picture thereon to conform to the existing orientation of the outlet into which the assembly is plugged

Disposable urinary pad

Abstract: The invention provides a disposable urinary pad having high liquid impact capacity, high liquid retention, and allows the skin of the wearer to remain dry. The pad is comprised of a liquid-impermeable, substantially flexible shell containing a fibrous web superstructure substantially filling the shell and an absorbent medium between the superstructure and the bottom of the shell.

Acoustic radiation from fluid‐loaded infinite circular cylinders with doubly periodic ring supports

Abstract: Analytic expressions are derived for the farfield acoustic radiation from a point‐driven, fluid‐loaded circular cylindrical shell reinforced with doubly periodic ring supports. The ring supports interact with the cylindrical shell only through normal forces. The model includes the effects of fluid loading and interactions between supports. Predictions are compared to measured farfield acoustic radiation data taken on a finite circular cylindrical shell with doubly periodic ring supports. Characteristics of the acoustic radiation are examined by example and some physical interpretation of significant features are offered.

A total lagrangian formulation for the geometrically nonlinear analysis of structures using finite elements. Part I. Two-dimensional problems: Shell and plate structures

Abstract: A total Lagrangian finite element formulation for the geometrically nonlinear analysis (large displacement/large rotations) of shells is presented. Explicit expressions of all relevant finite element matrices are obtained by means of the definition of a local co-ordinate system, based on the shell principal curvature directions, for the evaluation of strains and stresses. A series of examples of nonlinear analysis of shell and plate structures is given.

Acoustic spectrogram and complex‐frequency poles of a resonantly excited elastic tube

Abstract: We present a study of the resonance scattering undergone by an air‐filled hollow elastic cylinder excited by an incident plane acoustic wave. We construct the boundary value problem, obtain its classical solution, the solution based on the Resonance Scattering Theory (RST), and generate a variety of useful computed results, some of which are later compared to experimental observations recently performed in France. We present highly accurate expressions for the phase and group velocities and for the phase and group attenuations of the first few surface waves circumnavigating (the extreme cases) of rigid and soft cylinders, and display these dispersion plots in all instances. We analyze the modal backgrounds and modal resonances of the shell, display them in a wide spectral band, determine the SEM‐type pole‐position diagram in the complex k1a plane, and obtain and display the background‐suppressed cross section of the tube. This result serves to generate the acoustic spectrogram of the shell as well as to s...

Blind rivet assembly

Abstract: A blind, self-plugging rivet assembly for securing together two members (42, 43) is of the type comprising a tubular shell (13) with an enlarged head (14) at one end, and a stem (12) which extends through the bore (15) of the shell, the stem having an enlarged head (38) beyond the tail end (18) of the shell The shell has a weakened zone (19) formed by three slits (22) extending along part of the shell shank and spaced apart equiangularly around it The stem head (38) lies beyond the shell tail end, and has an underhead surface (39) which is slightly convex and is bounded by a sharp edge (40) The stem has a pulling portion (32) connected by a breakneck to a plugging portion (31) which is an interference fit in the shell bore Adjacent the breakneck the plugging portion has a cylindrical skirt which, when the rivet has been installed, can be deformed outwardly to lock the plugging portion to the shell A bead on the stem guides the tool for deforming the skirt

Influence of Geometric Imperfections and In-Plane Constraints on Nonlinear Vibrations of Simply Supported Cylindrical Panels

Abstract: This papers deals with the effects of initial geometric imperfections on large-amplitude vibrations of cylindrical panels simply supported along all four edges. In-plane movable and in-plane immovable boundary conditions are considered for each pair of parallel edges. Depending on whether the number of axial and circumferential half waves are odd or even, the presence of geometric imperfections (taken to be of the same shape as the vibration mode) of the order of the shell thickness may significantly raise or lower the linear vibration frequencies. In general, an increase (decrease) in the linear vibration frequency corresponds to a more pronounced soft-spring (hard-spring) behavior in nonlinear vibration.

Shell forming system

Abstract: An apparatus is provided for forming gas-filled spheres of metal, glass or other material, which produces spheres (12) of uniform size and wall thickness in a relatively simple system. The system includes concentric nozzles, including an inner nozzle (18) through which gas flows and and an outer nozzle (20), which jointly define an annular passageway (50) through which a liquid flows. The flow rates are adjusted so that the gas flows at greater velocity than does the liquid, out of their respective nozzles, e.g. three times as great, in order to produce an extrusion (30) which undergoes axisymmetric oscillations resulting in the pinch off into hollow spheres with very uniform spacing. The system is useful not only where gas-filled spheres are required, but also is useful to accurately control the dispensing of solid, liquid, or gaseous materials.

Scroll machine with discharge passage through orbiting scroll plate and associated lubrication system

Abstract: A scroll compressor enclosed in a hermetic shell, wherein part of the volume enclosed by the shell is at suction pressure and part is at discharge pressure. The compressor includes both a stationary and a driven scroll plate, with intermeshed involute wrap elements attached to the plates for defining pockets in which fluid is compressed as a drive shaft connected to the driven plate causes it to orbit relative to the stationary scroll plate. A passage disposed within the driven plate and adjacent its axial center conveys compressed fluid through the plate and into a cavity formed in the end of the drive shaft. Oil entrained in the compressed fluid is thrown radially outward within the cavity, due to centrifugal force, and is thereby separated from the compressed fluid. The oil then flows through an adjacent bearing, and is thrown radially outward, creating a spray that impinges on a seal which abuts the back surface of the driven scroll plate. A drive shaft bearing also receives lubrication as the oil flows back into the reservoir at the bottom of the shell.

Free vibration of a clamped-free circular cylindrical shell partially filled with liquid—Part I: Theoretical analysis

Abstract: Theoretical analyses are presented for the linear free vibration of a clamped-free cylindrical shell partially filled with an incompressible, inviscid liquid. For the vibration of the shell itself, the dynamic version of the Donnell equations was used and the problem was solved with the modified Galerkin procedure, taking the effect of the axisymmetric deformation due to the static liquid pressure into consideration. Concerning the vibration relevant to the liquid motion, the solution for the velocity potential was assumed as a sum of two sets of linear combinations of the suitable harmonic function, the unknown parameters of which were imposed to satisfy both boundary conditions along the wetted shell wall and the free liquid surface in a sense of appropriate series expansions. The procedure stated in the foregoing leads to a determinantal equation for the determination of the natural frequencies of the present shell-liquid system. To compare with the experimental results which will be stated in a companion paper, 14 detailed numerical results will be presented in another companion paper 13 on the free vibration characteristics of the two test cylinders partially filled with water.

Thermomechanical behavior of the solidifying shell within continuous-casting billet molds-a numerical approach

Abstract: A two-dimensional numerical model is given for the analysis of the coupled thermal and mechanical behavior of the solidifying shell within the mold during continuous casting of steel. The influence of different mold wall profiles on gap formation and heat flow during casting of billets is investigated. The calculated temperatures, stresses, and strains in the shell are used to estimate the risk for formation of longitudinal cracks. The effect of an initiated and growing macroscopic subsurface crack on the shell behavior is studied. The genesis of surface cracks is discussed. The calculated results are shown to be in reasonable agreement with experimental observations reported in the literature.

Thin shell concrete wall panel

Abstract: A building panel is described which can be used for either walls or floors. It comprises a thin shell unit of reinforced, monolithic cementitious material having a large, planar outer face and an inner face interconnected by parallel end edges and parallel side edges. A plurality of stud members are partially embedded in the inner face of the cementitious shell, these stud members being parallel to each other, laterally spaced from each other and being fabricated of about 15 to 25 gauge galvanized steel sheet. This steel sheet material is shaped to provide a web portion with one longitudinal edge of the web being shaped to lock the stud within the concrete shell and the longitudinal edge of the web remote from the concrete shell comprising an L-shaped flange defining the outer surface of the stud member to which a finished panel may be attached. Channel-shaped metal beam members connect the ends of the studs.

Rigid polyethylene carry golf bag with stand

Abstract: A golf club bag having, an integral outer shell, a top panel closing the upper end of the shell, with shaft apertures therein, a core within the shell, stops at the lower end of the core, guide channels in the core forming handle recesses, a handle on the exterior of the shell, and, releasable closure for the upper end of the shell.

Free vibration of a clamped-free circular cylindrical shell partially filled with liquid—part III: Experimental results

Abstract: To compare with the theoretical results presented in Parts I and II, 1,2 detailed experimental results have been obtained on the free vibration of a clamped-free cylindrical shell partially filled with liquid. Two polyester test cylinders with radius 100 mm, thickness 0·25 mm, and lengths 114 and 227 mm were used, and the filling ratio of the contained water was varied from 0 to 1·0 stepwise by 0·25 increments. Experiments were carried out by exciting the shell wall with two small shakers located at diametrically opposite positions and by observing the resonant responses of the shell with a noncontacting proximeter utilizing fiberglass optics. Excellent agreement between theory and experiment was demonstrated for the natural frequencies and the corresponding wave numbers concerning the lower-order natural vibrations dominated by the shell wall response. Variations of the mode shape with the circumferential wave number and the liquid depth were also examined, and were found to compare favourably with those predicted theoretically.

Removable double-action rope grip

Abstract: A rope grip which comprises a shell (12) and a plate (16) defining a first gripping surface and a cylinder (20) defining a second gripping surface is disclosed. The two surfaces are in a facing spaced relationship and define a passage (30) for receiving a rope. The cylinder travels in an angular field of motion with respect to the plate which causes a rope of appropriate size to become jammed between the plate and the cylinder depending upon the position of the cylinder. An operating arm (18) is mechanically coupled to the cylinder in order to control its position and accordingly, the distance between the surfaces of the plate and the cylinder.

Rigid make up compact with a flexible inner shell frame

Abstract: A powder compact comprises a base of relatively rigid plastics material which receives a flexible shell frame, by ultrasonic welding or catch-engagement, and the relatively rigid lid of the compact is hinged to the shell frame. Furthermore, the relatively elastic shell frame provides a convenient vehicle for carrying the resilient catch of the compact. Additionally, opening members are provided to bias the lid towards the open position.

Dynamic Stresses and Displacements in Buried Pipe

Abstract: Dynamic response of a pipeline buried in a semi‐infinite elastic medium is investigated. The pipeline is modeled as a circular cylindrical shell of small thickness. The incident disturbances are assumed to be plane waves moving perpendicular to the axis of the pipeline. Thus, the problem is either one of plane strain, which will be examined herein, or antiplane strain. Two problems are considered: (1) The pipe is surrounded by a homogeneous soft soil; and (2) the pipe lies in a cylinder of soft soil, which is surrounded by a rock‐like material. It is shown by comparison that the stresses and displacements are significantly modified in the latter case. The response is also found to be considerably influenced by the frequency of the incident wave and depth of the embedment.

Factors Affecting the Formation of Shell and Longitudinal Cracks in Mold during High Speed Continuous Casting of Slabs

Abstract: Factors affecting the formation of shell and longitudinal cracks on the shell have been investigated for high speed continuous casting of slabs.Withdrawal speed of slab, stream velocity from submerged nozzle, mold taper, and mold oscillation have shown respective influence on the formation of shell. Their effects have been analyzed quantitatively. Also, characteristics of the heat extraction from and resulting stress in the shell have been examined with respect to the crack formation.These observations have resulted in countermeasures to enhance uniform shell formation in mold and prevent the cracks on the slabs.

Shell reforming method and apparatus

Abstract: Method and apparatus for forming or reforming the shell of a two-piece container includes forming a cup shaped member in an upside down condition, reverse drawing the shell to form an over length chuckwall loosely holding the shell while pulling the excess material from the chuckwall into the bottom panel of the shell. The apparatus comprises tooling incorporated into a double acting press and including a punch core carried by the inner ram and an opposed die core carried by the bottom platen, a first pressure member carried by the outer ram and a die core ring fluidly supported on the bottom platen opposed to the pressure member and a punch shell carried on the inner ram. A second fluid pressure sleeve means is carried on the bottom platen in opposed relationship to the punch shell and a knockout piston is also carried by the lower platen opposed to the punch core and encircling the die core. The tooling is arranged such that the first pressure sleeve holds the material against the die core ring under fluid pressure while the punch shell draws the material over the die core ring to preliminarily form the chuckwall. The second pressure sleeve is movable into engagement with the die core ring under pressure from the punch shell so that, as the punch core terminates its travel, holding pressure is reduced as the over length material is pulled into the central area of the end panel.

X-rays from Eta Carinae

Abstract: X-ray observations of Eta Car obtained with the high-resolution imager and solid-state spectrometer of the Einstein observatory are reported and interpreted in terms of a two-shell model. A soft component with temperature 5 million K is located in the expanding outer shell, and the hard core component with temperature 80 million K is attributed to the interaction of a high-velocity stellar wind from the massive central object with the inner edge of a dust shell. Model calculations based on comparison with optical and IR data permit estimation of the mass of the outer shell (0.004 solar mass), the mass of the dust shell (3 solar mass), and the total shell expansion energy (less than 2 x 10 to the 49th ergs).