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The influences of viscous shear stresses on the squeezing film behaviors in porous journal bearings with infinite length are analyzed. Based on the Brinkman model, two general coupled Reynolds‐type equations derived between two curved surfaces are applied to evaluate the bearing characteristics. According to the results obtained, the Brinkman model predicts quite different squeezing film performances to those obtained by using the slip‐flow model and the Darcy model. In addition, the quantitative effects of viscous shear stresses of the Brinkman model upon the porous squeezing film characteristics are more pronounced for porous journal bearings with moderate permeability parameters and higher eccentricity ratios.

LONG before man learnt to make fire by the friction of wood, he experienced the burden of friction in dragging home his kill. Perhaps it is not too fanciful to suppose that the torn sides of his beast gave the first solid lubricant. Blood and mutton fat were seriously recommended as lubricants for church bell trunnions as recently as the 17th century. Indoed we still reckon fatty acids the best of all boundary lubricants. The range of man's activities has increased enormously in the present century, and particularly in the last few decades. Men have circled the earth in space; a space ship is on its way to examine another planet; terrestrial man is boring to the bottom of the earth's crust; others have descended to the depths of the ocean, and oven established a home on the floor of the Mediterranean, Speeds have increased by factors of thousands, temperatures range from near absolute zero to thousands of degrees; and a new environment of high‐intensity nuclear radiation has been created. Still, objects must move over and along each other in these exotic conditions; and to a large extent solid lubricants can provide the answer to the frictional problems.

The purpose of this paper is to study the seismic performance of the energy-saving block and invisible multi-ribbed frame composite walls (EBIMFCW), changing the shear-span ratio as the test parameter, the low-cycle reciprocating loading tests of six 1/2 scale wall models were carried out.

The test design method and analysis are used for the seismic performance of the EBIMFCW.

With the increase of shear-span ratio: the walls tend to occur bending failure even more, the initial stiffness of the wall decreases, the overall ductility of the wall is improved and the walls tend to occur bending failure.

The previous studies do not involve the seismic performance of EBIMFCW under different shear-span ratios. Therefore, the paper studies the hysteresis behavior, ductility, stiffness degradation and energy dissipation performance of EBIMFCW under different shear-span ratios.

To the Editor. DEAR SIR: I am most happy to take advantage of your suggestion that 1 write a letter summarizing my impressions of the papers presented at the New York meeting on fatigue, with particular reference to my paper in the January issue (on the Mechanism of Fatigue). As you know, I did not attend this meeting and therefore cannot give you a complete review, including the discussions. Furthermore, it has been impossible to read all of the 69 papers that I recently received. However, I have reviewed the ten papers on Basic Studies and have had the privilege of discussing these at some length with Dr Maxwell Gensamer, who was chairman of this part of the session. Since you will undoubtedly publish a detailed review of all the papers, I shall not attempt to treat them individually, but will simply describe what I believe to be the present situation regarding the theory of fatigue.

The viscosity of surface coating fluids is a property of considerable importance in their manufacture and application. This is apparent from a consideration of, for example, the various stages involved in the production and application of a decorative paint.

Coatings are widely used in gears to keep interface from wearing excessively. The purpose of this paper is to study the effect of coating properties and working conditions on the pressure, the shear traction, stresses as well as the fatigue life of spur gear.

A numerical contact fatigue life model of a coated spur gear pair under elastohydrodynamic lubrication (EHL) is developed based on the characteristics of gear geometry and kinematics, lubrication conditions and material properties. Frequency response functions and the discrete convolute and fast Fourier transform (DC-FFT) algorithm are applied to obtain elastic deformation and stress. Mutil-axial fatigue criteria are used to evaluate the contact fatigue life based upon the predicted time-varying stress fields of coated bodies.

The maximum Mises stress decreases while the fatigue life increases as the coating modulus decreases. A thinner coating leads to a longer life and a smaller maximum Mises stress for hard coatings. The load has more significant effect on the contact fatigue life of soft coatings.

The developed model can be used to evaluate the contact fatigue life of coated gear under EHL and help designers analyze the effect of coating elastic modulus and thickness on the contact pressure, film thickness and stress.

The purpose of this paper is to analyse dynamic drape behaviour of eight different types of woollen fabrics each treated by three different finishing processes.

A new apparatus was used to evaluate the dynamic drape formation process of woollen fabrics during the rotation of the samples at different speed grades of 0 (static drape), 30, 60, 90, 120, 150 and 180 rev/min for each sample. The computerised image analysis method was used to measure the drape coefficients (DCs).

As a result of experiments, it was found that shearing, calendaring, pressing processes affected the drapability and drape behaviour negatively, but belt pressing treatment and decatising process improved the drapability and the drape behaviour for all fabrics. Furthermore, there is a reverse relationship between fabric weight and drape behaviour. As the fabric weight increases, DC value increases due to the increase of fabric tightness.

To date, although many researchers have studied the static draping behaviour, the studies regarding the dynamic drape behaviour of the fabrics are quite limited to an extent. Besides, none of these studies regarding the drape behaviour have investigated the effects of different finishing processes on the drape behaviour of wool fabrics.

IN the course of stressing certain front cross members of an engine mounting it was found necessary to determine the shear'stress on various sections of the cross members as accurately as possible. These cross members were by no means of uniform cross‐section, so that it was considered desirable to investigate, a formula which would give shear stress in a tapered beam. The “classical” methods evolved by Messrs. Coker and Filon in their Treatise on Photo‐elasticity and by Mr. Atkin in AIRCRAFT ENGINEERING, Vol. X, November and December, 1938, pp. 347–351 and 371–374 were found to be too elaborate. In September, 1942, Messrs. Pugsley and Weatherhead contributed an article entitled “The Shear Stresses in Tapered Beams”, to the Journal of the Royal Aeronautical Society. These authors start with a standard expression for shear stress based on the equilibrium of a portion of a beam and apply it to the solution of some examples. In the course of my investigations, it has been found possible to extend the “engineering” analysis of shear stress in beams of uniform section to beams of variable cross‐section. The expression for the determination of shear stress thus arrived at is very convenient and quite suitable for graphical methods. However, in the case of symmetrically tapering beams, an approximate formula has been developed for the shear stress in terms of shear force, bending moment, taper angle and section inertia and this formula is much more convenient and simple to apply than the standard expression used by Messrs. Pugsley and Weatherhead.

A series of articles explaining in simple language the fundamentals of Lubrication

Paints (surface coatings), primarily used to protect various substrates from the corroding action of acidic and alkaline substances, largely contain polymers as coating formulations. Examples of generally used polymers are: butadiene based (space), epoxy resins and silicone fluids (concrete vinyl polymers and polyurethanes (optical fibres) alkyds and acrylics (electronics) and polyester resins (wood, metal and fibre‐glass reinforcements). The binder‐pigment interaction controls important properties like hardness, flexibility, permeability, adhesion, gloss, and mechanical properties and contributes finally to the success or otherwise of the paint as a protective surface‐coating. Excellence of pigment dispersion and paint performance are thus intimately related.