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Articles 1 - 14 of 14

Full-Text Articles in Mechanical Engineering

Non-Linear Interactions Of Acoustic Fields With Plates Under Harmonic Excitations, A. Nayfeh, S. Kelly Apr 2015

Non-Linear Interactions Of Acoustic Fields With Plates Under Harmonic Excitations, A. Nayfeh, S. Kelly

Dr. S. Graham Kelly

The method of renormalization is used to determine a uniformly valid expansion for the problem of non-linear interactions of acoustic fields with plates under harmonic excitations. The expansion obtained is in agreement with that obtained by Ginsberg, who used the method of strained co-ordinates to render the potential uniform and then used the method of renormalization to render the non-uniform pressure and velocity components calculated from the resulting potential uniform.


Stress Response Of A Rubber Block With Frictional Contact Under Axial Loading, J. Suh, S. Kelly Apr 2015

Stress Response Of A Rubber Block With Frictional Contact Under Axial Loading, J. Suh, S. Kelly

Dr. S. Graham Kelly

Rubber blocks (or springs) are structural components widely used in many applications. Design characteristics of a rubber block under axial loading are an apparent modulus (or compression modulus) and normal and shear stresses on contact surfaces. These are affected by a contact condition of the rubber block in contact with two rigid plates and the shape of the block. The problem of a rubber block bonded to two rigid plates has been solved using various approaches. In contrast, for a rubber block whose one surface is bonded to a rigid plate and the other surface in contact with a frictional ...


Development Of Normal Mode Theory For Multi-Degree-Of-Freedom Systems Using An Energy Inner Product, S. Kelly Apr 2015

Development Of Normal Mode Theory For Multi-Degree-Of-Freedom Systems Using An Energy Inner Product, S. Kelly

Dr. S. Graham Kelly

No abstract provided.


Fundamentals Of Mechanical Vibrations, S. Kelly Apr 2015

Fundamentals Of Mechanical Vibrations, S. Kelly

Dr. S. Graham Kelly

This text is designed for undergraduate courses in vibrations taught in departments of mechanical engineering. It provides detailed explanations of fundamental aspects of vibrations such as the derivation of differential equations, covers physical interpretation of phenomena using energy methods, and includes chapters on vibration control and nonlinear vibrations. Detailed coverage of the equivalent systems method allows modelling of all one-degree-of-freedom linear systems by a mass-spring-dashpot system.


Non-Linear Propagation Of Directional Spherical Waves, S. Kelly, A. Nayfeh Apr 2015

Non-Linear Propagation Of Directional Spherical Waves, S. Kelly, A. Nayfeh

Dr. S. Graham Kelly

The method of renormalization is used to determine a uniformly valid expansion for the problem of non-linear waves produced in a fluid by spatially non-uniform simple harmonic motion of the surface of a sphere. The effect of dimensionless quantities upon the acoustic shock-formation distance is examined.


Non-Linear Propagation Of General Directional Spherical Waves, S. Kelly, A. Nayfeh Apr 2015

Non-Linear Propagation Of General Directional Spherical Waves, S. Kelly, A. Nayfeh

Dr. S. Graham Kelly

The method of renormalization is used to determine a uniformly valid expansion for the problem of non-linear waves produced in a fluid by the general harmonic pulsations of a sphere. For a uniform expansion, only the radial distance needs to be strained. The effect of dimensionless quantities upon the shock-formation distance is examined.


Mechanics Of Rubber Shear Springs, A. Gent, J. Suh, S. Kelly Apr 2015

Mechanics Of Rubber Shear Springs, A. Gent, J. Suh, S. Kelly

Dr. S. Graham Kelly

FEA calculations have been carried out for a model rubber shear spring, consisting of a block of a highly elastic material, bonded between two rigid parallel plates and sheared by displacing one of the plates parallel to the other in its own plane. The block was prevented from deforming in the perpendicular direction, and thus was deformed in plane strain. Stress distributions along the bond-line and the center-line are reported and compared with those expected from the theory of large elastic deformations. Unexpected tensile stresses were found to develop in the interior of the sheared block. They are attributed to ...


Natural Frequency And Mode Shape Perturbations For Linear Multidegree Of Freedom Systems, S. Kelly Apr 2015

Natural Frequency And Mode Shape Perturbations For Linear Multidegree Of Freedom Systems, S. Kelly

Dr. S. Graham Kelly

No abstract provided.


Free Vibrations Of Elastically Connected Stretched Beams, S. Kelly, Shirish Srinivas Apr 2015

Free Vibrations Of Elastically Connected Stretched Beams, S. Kelly, Shirish Srinivas

Dr. S. Graham Kelly

A general theory for the determination of natural frequencies and mode shapes for a set of elastically connected axially loaded Euler–Bernoulli beams is developed. A normal-mode solution is applied to a set of non-dimensional coupled partial differential equations. The natural frequencies are the eigenvalues of a matrix of differential operators. The matrix operator is shown to be self-adjoint leading to an orthogonality condition for the mode shapes. In the special case of identical beams, it is shown that the natural frequencies are organized into sets of intramodal frequencies in which each mode shape is a product of a spatial ...


Nonlinear Phenomena In A Column Of Liquid In A Rotating Manometer, S. Kelly Apr 2015

Nonlinear Phenomena In A Column Of Liquid In A Rotating Manometer, S. Kelly

Dr. S. Graham Kelly

No abstract provided.


Free And Forced Vibrations Of Elastically Connected Structures, S. Kelly Apr 2015

Free And Forced Vibrations Of Elastically Connected Structures, S. Kelly

Dr. S. Graham Kelly

A general theory for the free and forced responses of elastically connected parallel structures is developed. It is shown that if the stiffness operator for an individual structure is self-adjoint with respect to an inner product defined for , then the stiffness operator for the set of elastically connected structures is self-adjoint with respect to an inner product defined on . This leads to the definition of energy inner products defined on . When a normal mode solution is used to develop the free response, it is shown that the natural frequencies are the square roots of the eigenvalues of an operator that ...


Shear Of Rubber Tube Springs, J. Suh, A. Gent, S. Kelly Apr 2015

Shear Of Rubber Tube Springs, J. Suh, A. Gent, S. Kelly

Dr. S. Graham Kelly

Rubber tube springs consist basically of cylindrical rubber tubes bonded on their inner and outer curved surfaces to rigid cylindrical tubes. They are widely used as flexible linkages, for example in vehicle suspensions. Rotation of one rigid tube with respect to the other about their common axis subjects the rubber tube to azimuthal shear. Displacement of one rigid tube with respect to the other along their common axis puts the rubber tube into axial shear. Using FEA, we have calculated the stresses set up in both cases, for a long rubber tube of a non-linearly elastic (neo-Hookean) material. The results ...


Non-Linear Propagation Of Directional Cylindrical Waves, S. Kelly, A. Nayfeh Apr 2015

Non-Linear Propagation Of Directional Cylindrical Waves, S. Kelly, A. Nayfeh

Dr. S. Graham Kelly

The method of renormalization is used to determine a uniformly valid expansion for the problem of non-linear waves produced in a fluid by the harmonic pulsations of a finite circular cylinder. For a uniform expansion, both the radial and axial distances need to be strained. The effect of dimensionless quantities upon the acoustic shock-formation distance is examined. The results show that the wave produced consists of a number of groups that propagate without any mutual interaction.


Schaum's Interactive Outline Of Mechanical Vibrations And Print Outline, S. Kelly Apr 2015

Schaum's Interactive Outline Of Mechanical Vibrations And Print Outline, S. Kelly

Dr. S. Graham Kelly

No abstract provided.