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Distribution of deformation under a ball indentation
LITERATURE
AND
CURRENT
EVEKTS
clemental strips in the contact zone. The effects of surface tractions and geometric conformity between the rolling element and its track are considered. From this solution it is possible to derive the over-all creep arising from such microslip. In particular the condition of zero over-all creep is considered as being a useful design criteria for minimum wear in rolling situations. (See also Wear, 7 (1964) 516.)
The Effect of Surface Roughness on Fluid Drainage from Metal Surfaces. J. Bornong, ASLE Trans., 7 (1964) 383-388; 4 figs., 4 tables, 9 refs. Measurements on the drainage of several mineral oils and a diester from vertical metal surfaces of different roughnesses have been carried out. Metals studied were low-carbon steel, aluminum, and silver-copper alloy (90 Ag-IO Cu). The method was adapted from one devised by Bikerman and applied by him to stainless steel, in which mineral oil retention by rough surfaces was compared with retention by smooth surfaces. High correlation has been obtained between surface roughness, as measured by a stylus instrument, and thickness of an apparently stagnant layer of oil. The correlation is highest when the roughness is measured in the direction of drainage. Equations for calculating the total thickness and volume of fluid retained by smooth surfaces have been reconfirmed.
The Importance of Humidity in Friction Measurement. G. S. Reichenbach, Lubvication Elzg., 20 (II) (1964) 409-413; II figs., 6refS. Sliding friction measurements are made on a variety of material combinations including metals, carbons, plastics, and glass as a function of relative humidity. In most situations humidity is found to cause large scale changes in friction level but the direction of the change may be positive or negative depending upon the specific material combinations. Friction changes for some material combinations are found to be nonreversing when humidity is returned to the original value. No general theory is proposed but several possible competing mechanisms are discussed. Friction in Stacked-disk Springs. D. H. Thiel, ASME Paper No. 63.WA-270, 1963, 7 pages. Experiments to determine the amount of friction that would exist in various possible series and parallel stacking combinations of disk springs for the Navy’s 6oo-ft-diameter radio telescbpe are summarized in plots of friction US. applied load. Indications were that the most efficient system using disk
321 springs involves stacking several disks in series without use of parallel stacked disks.
the Static Coefficient at High Specific Pressure by Strain Gauges. Ch. Go-Khua and O.V. Rumyantsev, Russ. Eng. J., 42 (12) (1962) 16-18. (Translation of Vestn. Mashinostr., 42 (12) (1962) 22-24 by
Determining
Production Engineering Research Association of Gt. Britain.) For abstract see AppZ. Mech. Rev., 17 (IO) (1964) 855. Distribution of Deformation under a Ball Indentation. Yu. E. Bondarev, V. V. Varnello and G. I. Tsibin, Ind. Lab. (USSR), 29 (5) (Nov. 1963) 640-642. (Translation of Zauod. Lab., 29 (5) (1963) 604-606 by Instrument Society of America, Pittsburgh, Pa.) For abstract see Appl. Mech. Rev., 17 (II)
(1964) 949. The Coefficient of Friction in Tight-fitting Threaded Joints. S. N. Zakharov, Russ. Eng. J.. IO (1963) 15-17. (Translation of Vestn. Mashinostr., 42 (IO) (1963) 24-25 by Production Engineering Research Association of Gt. Britain.) For abstract see Appl. Mech. Rev., 17 (12) (1964)
1000.
Calculation of Sliding Friction between Solids and Soils. G. S. Gura, Russ. Eng. J., 43 (7) (1964) 20-22. (Translation of Vestn. Mashinostr., 43 (7) (1964) 29-32 by Production Engineering Research Association of Gt. Britain.) For abstract see Appl. Mech. Rev.,
17 (12)
(7964) ‘047. 2.2. Material
Properties
Friction and Wear of Diamond in High Vacuum. F. P. Bowden and A. E. Hanwell, Nature, 201 (1964) 1279-1281 ; 5 figs., IO IXfS. When the diamond surfaces are slid on one another in a high vacuum, the adsorbed films are removed and the naked surface of the crystal is exposed. The very high value of the friction (p - I) shows that the adhesion at the contact regions of the surface asperities is very strong and the force required to shear them is close to the shear strength of diamond itself. The severe wear which occurs in high vacuum is probably due to cracking under a combination of the normal stresses and the large tangential stresses in the surface which is induced by the strong adhesion at the regions of contact. In outer space, the contaminating films which evaporate away or which are worn off will not be replaced, and “jewel bearings” may give high friction and wear. Wear,
8 (1965) 320-331
AND
CURRENT
EVEKTS
clemental strips in the contact zone. The effects of surface tractions and geometric conformity between the rolling element and its track are considered. From this solution it is possible to derive the over-all creep arising from such microslip. In particular the condition of zero over-all creep is considered as being a useful design criteria for minimum wear in rolling situations. (See also Wear, 7 (1964) 516.)
The Effect of Surface Roughness on Fluid Drainage from Metal Surfaces. J. Bornong, ASLE Trans., 7 (1964) 383-388; 4 figs., 4 tables, 9 refs. Measurements on the drainage of several mineral oils and a diester from vertical metal surfaces of different roughnesses have been carried out. Metals studied were low-carbon steel, aluminum, and silver-copper alloy (90 Ag-IO Cu). The method was adapted from one devised by Bikerman and applied by him to stainless steel, in which mineral oil retention by rough surfaces was compared with retention by smooth surfaces. High correlation has been obtained between surface roughness, as measured by a stylus instrument, and thickness of an apparently stagnant layer of oil. The correlation is highest when the roughness is measured in the direction of drainage. Equations for calculating the total thickness and volume of fluid retained by smooth surfaces have been reconfirmed.
The Importance of Humidity in Friction Measurement. G. S. Reichenbach, Lubvication Elzg., 20 (II) (1964) 409-413; II figs., 6refS. Sliding friction measurements are made on a variety of material combinations including metals, carbons, plastics, and glass as a function of relative humidity. In most situations humidity is found to cause large scale changes in friction level but the direction of the change may be positive or negative depending upon the specific material combinations. Friction changes for some material combinations are found to be nonreversing when humidity is returned to the original value. No general theory is proposed but several possible competing mechanisms are discussed. Friction in Stacked-disk Springs. D. H. Thiel, ASME Paper No. 63.WA-270, 1963, 7 pages. Experiments to determine the amount of friction that would exist in various possible series and parallel stacking combinations of disk springs for the Navy’s 6oo-ft-diameter radio telescbpe are summarized in plots of friction US. applied load. Indications were that the most efficient system using disk
321 springs involves stacking several disks in series without use of parallel stacked disks.
the Static Coefficient at High Specific Pressure by Strain Gauges. Ch. Go-Khua and O.V. Rumyantsev, Russ. Eng. J., 42 (12) (1962) 16-18. (Translation of Vestn. Mashinostr., 42 (12) (1962) 22-24 by
Determining
Production Engineering Research Association of Gt. Britain.) For abstract see AppZ. Mech. Rev., 17 (IO) (1964) 855. Distribution of Deformation under a Ball Indentation. Yu. E. Bondarev, V. V. Varnello and G. I. Tsibin, Ind. Lab. (USSR), 29 (5) (Nov. 1963) 640-642. (Translation of Zauod. Lab., 29 (5) (1963) 604-606 by Instrument Society of America, Pittsburgh, Pa.) For abstract see Appl. Mech. Rev., 17 (II)
(1964) 949. The Coefficient of Friction in Tight-fitting Threaded Joints. S. N. Zakharov, Russ. Eng. J.. IO (1963) 15-17. (Translation of Vestn. Mashinostr., 42 (IO) (1963) 24-25 by Production Engineering Research Association of Gt. Britain.) For abstract see Appl. Mech. Rev., 17 (12) (1964)
1000.
Calculation of Sliding Friction between Solids and Soils. G. S. Gura, Russ. Eng. J., 43 (7) (1964) 20-22. (Translation of Vestn. Mashinostr., 43 (7) (1964) 29-32 by Production Engineering Research Association of Gt. Britain.) For abstract see Appl. Mech. Rev.,
17 (12)
(7964) ‘047. 2.2. Material
Properties
Friction and Wear of Diamond in High Vacuum. F. P. Bowden and A. E. Hanwell, Nature, 201 (1964) 1279-1281 ; 5 figs., IO IXfS. When the diamond surfaces are slid on one another in a high vacuum, the adsorbed films are removed and the naked surface of the crystal is exposed. The very high value of the friction (p - I) shows that the adhesion at the contact regions of the surface asperities is very strong and the force required to shear them is close to the shear strength of diamond itself. The severe wear which occurs in high vacuum is probably due to cracking under a combination of the normal stresses and the large tangential stresses in the surface which is induced by the strong adhesion at the regions of contact. In outer space, the contaminating films which evaporate away or which are worn off will not be replaced, and “jewel bearings” may give high friction and wear. Wear,
8 (1965) 320-331