On Free Vibrations of a Thin Spinning Disk Stiffened With an Outer Reinforcing Ring

1988 ◽  
Vol 110 (4) ◽  
pp. 507-514 ◽  
Author(s):  
S. K. Sinha
Keyword(s):  
Data Storage ◽  
Free Vibrations ◽  
Circular Ring ◽  
Outer Edge ◽  
Design Parameters ◽  
Computer Data ◽  
Storage Devices ◽  
Small Deflection ◽  
Deflection Theory ◽  
Annular Disks

Thin spinning annular disks, which have widely varying applications ranging from inertial wheels in spacecraft to computer data storage devices, experience some inherent vibration problems during operation. One of the techniques to control the vibrations of the disk, being analyzed in this paper, is to stiffen it by attaching a reinforcing ring at its outer edge. The present work considers the effect of adding such a ring and discusses the changes in the natural frequencies for a large range of design parameters. The classical plate bending equation based upon small deflection theory which includes the contribution of rotational membrane stresses has been used in the eigenvalue formulation. Numerical results presented in a nondimensional form should be useful in predicting the dynamic response of such a disk stiffened with a circular ring under the spinning conditions.

The Bending of the Cylindrically Aeolotropic Plate

1944 ◽  
Vol 11 (3) ◽  
pp. A129-A133
Author(s):  
G. F. Carrier
Keyword(s):  
Radial Symmetry ◽  
Outer Edge ◽  
Circular Plates ◽  
Concentrated Force ◽  
Design Problems ◽  
Simply Supported ◽  
Uniform Shear ◽  
Small Deflection ◽  
Degree Of Anisotropy ◽  
Deflection Theory

Abstract In this paper, the small-deflection theory, applicable to plates of cylindrically aeolotropic material, is presented, and expressions are obtained for the moments and deflections produced by the following combinations of loading and boundary conditions: The disk clamped along its circumference and loaded by a uniform lateral pressure; the clamped disk loaded by a central concentrated force; the simply supported disk loaded by uniform edge moment; the disk with a rigid core clamped along its circumference and loaded by a central concentrated force; the ring clamped along its outer edge and loaded by a uniform shear distribution along the inner edge; the simply supported disk with an elastic isotropic core loaded by a uniform edge moment; and the disk under the loading given by p = p0r cos θ. The six symmetrical problems of this group were chosen for evaluation since they and their linear combinations comprise a large part of the total set of such problems. Curves are included showing, for three of the foregoing problems, the effect of the degree of anisotropy on the stresses. The practical application of solutions obtained by the following theory might lie, for example, in design problems involving circular plates which are built up of laminas of radial symmetry with different tangential and radial stiffnesses. The theory could also be applied to the design of circular concrete slabs with different amounts of reinforcing steel in the radial and tangential directions.

Functional Applications of Future Data Storage Devices

2021 ◽  
pp. 2001181
Author(s):  
Jia‐Qin Yang ◽  
Ye Zhou ◽  
Su‐Ting Han
Keyword(s):  
Data Storage ◽  
Storage Devices ◽  
Functional Applications ◽  
Future Data

scholarly journals Nanostructured ZnFe2O4: An Exotic Energy Material

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1286
Author(s):  
Murtaza Bohra ◽  
Vidya Alman ◽  
Rémi Arras
Keyword(s):  
Data Storage ◽  
Smart Materials ◽  
Energy Demand ◽  
Ceramic Materials ◽  
Magnetic Data ◽  
Processing Route ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Reduced Toxicity ◽  
Cation Arrangement

More people, more cities; the energy demand increases in consequence and much of that will rely on next-generation smart materials. Zn-ferrites (ZnFe2O4) are nonconventional ceramic materials on account of their unique properties, such as chemical and thermal stability and the reduced toxicity of Zn over other metals. Furthermore, the remarkable cation inversion behavior in nanostructured ZnFe2O4 extensively cast-off in the high-density magnetic data storage, 5G mobile communication, energy storage devices like Li-ion batteries, supercapacitors, and water splitting for hydrogen production, among others. Here, we review how aforesaid properties can be easily tuned in various ZnFe2O4 nanostructures depending on the choice, amount, and oxidation state of metal ions, the specific features of cation arrangement in the crystal lattice and the processing route used for the fabrication.

Oxidation of graphene ‘bow tie’ nanofuses for permanent, write-once-read-many data storage devices

2013 ◽  
Vol 24 (13) ◽  
pp. 135202 ◽  
Author(s):  
A C Pearson ◽  
S Jamieson ◽  
M R Linford ◽  
B M Lunt ◽  
R C Davis
Keyword(s):  
Data Storage ◽  
Storage Devices ◽  
Bow Tie

Overcoats and Lubrication for Thin Film Disks

MRS Bulletin ◽  
1990 ◽  
Vol 15 (3) ◽  
pp. 45-52 ◽  
Author(s):  
A.M. Homola ◽  
C.M. Mate ◽  
G.B. Street
Keyword(s):  
Thin Film ◽  
Data Storage ◽  
Magnetic Particles ◽  
Areal Density ◽  
Magnetic Film ◽  
Alloy Thin Film ◽  
Magnetic Media ◽  
Disk Interface ◽  
Storage Devices ◽  
Particulate Media

Metallic alloy thin film media and ever decreasing head-to-media spacing make severe demands on storage devices. Decreasing head-to-media separation is critical for high storage densities but it also leads to increased slider-disk interactions, which can cause slider and disk wear or even head crashes. Wear can also occur when drives start and stop when the slider contacts the disk at relatively high speeds. The reliability and durability of thin film disks, which provide much higher areal density than conventional oxide disks with particulate media, are achieved by the use of very thin overcoat materials and surface lubricants. This article summarizes the approaches taken in the industry to enhance the tribological performance of magnetic media, with special emphasis on the basic understanding of the processes occurring at the slider-disk interface.The continuous rise in the demand for storage capacity at a competitive price is the prime motivator of the changes we have seen in the data storage industry. It is clearly stimulating the present move away from particulate media, which has long dominated all fields of data storage, i.e., tape, rigid, and flexible disks, to the thin film storage media. Particulate storage devices use magnetic media formulated by dispersing magnetic particles, usually iron oxides, in an organic binder. In thin film storage devices, the storage medium is a continuous magnetic film, usually a cobalt alloy, made either by sputtering or by electroless plating.

The Mixed-Body Model: A Method for Predicting Large Deflections in Stepped Cantilever Beams

2021 ◽  
pp. 1-18
Author(s):  
Brandon Sargent ◽  
Collin Ynchausti ◽  
Todd G Nelson ◽  
Larry L Howell
Keyword(s):  
Large Deflections ◽  
Cantilever Beams ◽  
Element Analysis ◽  
Body Model ◽  
Minimal Error ◽  
Small Deflection ◽  
Rigid Body Model ◽  
Expected Values ◽  
Deflection Theory ◽  
Sample Set

Abstract This paper presents a method for predicting endpoint coordinates, stress, and force to deflect stepped cantilever beams under large deflections. This method, the Mixed-Body Model or MBM, combines small deflection theory and the Pseudo-Rigid-Body Model for large deflections. To analyze the efficacy of the model, the MBM is compared to a model that assumes the first step in the beam to be rigid, to finite element analysis, and to the numerical boundary value solution over a large sample set of loading conditions, geometries, and material properties. The model was also compared to physical prototypes. In all cases, the MBM agrees well with expected values. Optimization of the MBM parameters yielded increased agreement, leading to average errors of <0.01 to 3%. The model provides a simple, quick solution with minimal error that can be particularly helpful in design.

The Hexagonal ↔ Orthorhombic Structural Phase Transition in Claringbullite, Cu4FCl(OH)6

2021 ◽  
Author(s):  
Mark D. Welch ◽  
Jens Najorka ◽  
Michael S. Rumsey ◽  
John Spratt
Keyword(s):  
Phase Transition ◽  
Data Storage ◽  
Structural Phase Transition ◽  
Structural Changes ◽  
Structural Phase ◽  
Magnetic Behavior ◽  
Orthorhombic Phase ◽  
New Mineral ◽  
Storage Devices ◽  
Definition Of

ABSTRACT Frustrated magnetic phases have been a perennial interest to theoreticians wishing to understand the energetics and behavior of quasi-chaotic systems at the quantum level. This behavior also has potentially wide applications to developing quantum data-storage devices. Several minerals are examples of such phases. Since the definition of herbertsmithite, Cu3ZnCl2(OH)6, as a new mineral in 2004 and the rapid realization of the significance of its structure as a frustrated antiferromagnetic phase with a triangular magnetic lattice, there has been intense study of its magnetic properties and those of synthetic compositional variants. In the past five years it has been recognized that the layered copper hydroxyhalides barlowite, Cu4BrF(OH)6, and claringbullite, Cu4FCl(OH)6, are also the parent structures of a family of kagome phases, as they also have triangular magnetic lattices. This paper concerns the structural behavior of claringbullite that is a precursor to the novel frustrated antiferromagnetic states that occur below 30 K in these minerals. The reversible hexagonal (P63/mmc) ↔ orthorhombic (Pnma or Cmcm) structural phase transition in barlowite at 200−270 K has been known for several years, but the details of the structural changes that occur through the transition have been largely unexplored, with the focus instead being on quantifying the low-temperature magnetic behavior of the orthorhombic phase. This paper reports the details of the structural phase transition in natural claringbullite at 100−293 K as studied by single-crystal X-ray diffraction. The transition temperature has been determined to lie between 270 and 293 K. The progressive disordering of Cu at the unusual trigonal prismatic Cu(OH)6 site on heating is quantified through the phase transition for the first time, and a methodology for refining this disorder is presented. Key changes in the behavior of Cu(OH)4Cl2 octahedra in claringbullite have been identified that suggest why the Pnma structure is likely stabilized over an alternative Cmcm structure. It is proposed that the presence of a non-centrosymmetric octahedron in the Pnma structure allows more effective structural relaxation during the phase transition than can be achieved by the Cmcm structure, which has only centrosymmetric octahedra.

Study on Deformation and Stress of CRCP under Concentrated Vertical Load with Hollow Foundation

2011 ◽  
Vol 250-253 ◽  
pp. 3415-3420
Author(s):  
Xiao Bing Chen ◽  
Xiao Ming Huang ◽  
Jin Hu Tong
Keyword(s):  
Equivalence Principle ◽  
Transverse Crack ◽  
Torsion Theory ◽  
Slab Thickness ◽  
Vertical Load ◽  
Effective Measure ◽  
Small Deflection ◽  
Half Wave ◽  
Elastic Thin Plate ◽  
Deflection Theory

Based on the equivalence principle, the concentrated vertical load which acts on the Continuously Reinforced Concrete Pavement(CRCP) transverse crack is translated into the equivalent half-wave sine load by Fourier transform. According to the translation principle of the force, the half-wave sine vertical load acting on the CRCP transverse crack is decomposed to the half-wave sine vertical load and the torsion force acting on the center of CRCP. Lastly, the deflection, torsional displacement and stress formulas of CRCP under the concentrated vertical load with hollow foundation are put forward, which is on the basis of the small deflection theory of elastic thin plate and torsion theory. The results show that increasing the slab thickness is the most effective measure to reduce maximal deflection, distortion displacement and stress of CRCP concentrated vertical load with hollow foundation.

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