On the Indentation of a Transversely Isotropic Half-Space With Application to Thin Solid Lubricant Films

1993 ◽  
Vol 115 (4) ◽  
pp. 650-657 ◽  
Author(s):  
T. C. Ovaert
Keyword(s):  
Half Space ◽  
Elastic Constants ◽  
Solid Lubricant ◽  
Transversely Isotropic ◽  
Solid Lubricants ◽  
Lubricant Film ◽  
Contact Patch ◽  
Lubricant Films ◽  
Solid Lubricant Films ◽  
Plane Of Isotropy

In this investigation, the contact between a model rigid ellipsoidal asperity and the surface of an oriented solid lubricant film has been simulated using an analysis developed previously for contact of a transversely isotropic half-space. In this case, unlike most previous work, the plane of isotropy is oriented normal to the plane of contact, instead of parallel. Under this condition, the contact patch is of a general elliptical form, depending on the shape and orientation of the model asperity and on the elastic constants of the solid lubricants. Several applicable material compositions are examined using the analysis, and the influence of asperity shape and elastic constants in relation to friction and potential design of solid lubricant formulations is discussed.

Lubrication Mechanism of Solid Lubricants in Oils

1983 ◽  
Vol 105 (2) ◽  
pp. 245-252 ◽  
Author(s):  
T. Hisakado ◽  
T. Tsukizoe ◽  
H. Yoshikawa
Keyword(s):  
Solid Lubricant ◽  
Solid Lubricants ◽  
Optical Microscope ◽  
Wear Process ◽  
Copper Disk ◽  
Lubricant Films ◽  
Oil Flow ◽  
Solid Lubricant Films ◽  
Lubricating Properties ◽  
Worn Surfaces

Lubricating properties of machine oils containing such solid lubricants as (CF)n, MoS2, graphite, etc., were studied on a pin and disk machine by measuring an electric contact resistance and a friction force. After lubrication tests, solid lubricants films and transferred wear particles on worn surfaces have been observed by means of an XMA and an optical microscope. The wear mechanism of metals was analyzed considering a mean peak to peak distance and a mean depth of scratches on worn surfaces. The effects of particle size and concentration of (CF)n, and a suspending agent AD-6 on the friciton and wear process were also discussed. It was found that when the large number of (CF)n particles can penetrate into the interface in accordance with an oil flow, they show a good performance as a lubricant but solid lubricant films were not formed on worn surfaces besides graphite particles embedded on those of a copper disk.

Green’s Functions for Two-Phase Transversely Isotropic Materials

1979 ◽  
Vol 46 (3) ◽  
pp. 551-556 ◽  
Author(s):  
Y.-C. Pan ◽  
T.-W. Chou
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Elastic Constants ◽  
Transversely Isotropic ◽  
Two Phase ◽  
Closed Form Solutions ◽  
Isotropic Materials ◽  
Function Solution ◽  
Present Solution ◽  
Plane Of Isotropy

Closed-form solutions are obtained for the Green’s function problems of point forces applied in the interior of a two-phase material consisting of two semi-infinite transversely isotropic elastic media bonded along a plane interface. The interface is parallel to the plane of isotropy of both media. The solutions are applicable to all combinations of elastic constants. The present solution reduces to Sueklo’s expression when the point force is normal to the plane of isotropy and (C11C33)1/2 ≠ C13 + 2C44 for both phases. When the elastic constants of one of the phases are set to zero, the solution can be reduced to the Green’s function for semi-infinite media obtained by Michell, Lekhnitzki, Hu, Shield, and Pan and Chou. The Green’s function solution of Pan and Chou for an infinite transversely isotropic solid can be reproduced from the present expression by setting the elastic constants of both phases to be equal. Finally, the Green’s function for isotropic materials can also be obtained from the present solution by suitable substitution of elastic constants.

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