Journal of Mechanical Engineering Science

Interferometry is used to measure lubricant film thicknesses in a heavily loaded non-Hertzian contact. The results describing the sliding of a rigid plane over an elastic layer bonded to a rigid cylindrical substrate agree closely with theoretical values given by Hooke and O'Donoghue (1)^†.

Recent improvements in cycle counting methods have increased the value of the block load programme as a method of simulating the fatigue damage caused by random service loading.

It has already been observed that some of the lower load levels in certain block programmes make insignificant contributions to the total fatigue damage, and that the elimination of such levels can provide a very valuable method of accelerating tests.

This paper presents further evidence in support of this observation, and proposes an analytical method by which the damage significance of each block may be predicted, thus enabling a rapid selection of those levels which may be safely omitted.

One important way in which cutting lubricants operate is by reducing the degree of adhesion between the tool rake-face and the freshly formed chip surface. It is suggested that processes of molecular transport within a network of interfacial capillaries play a dominant role in controlling the effectiveness of cutting fluids, providing that they are capable of reaction with, or adsorption into, the metal surfaces.

In this paper, the ‘in-plane’ torsion testing of sheet metal is examined. The test itself was first proposed by Marciniak in order to ascertain the work hardening behaviour and fracture strain of sheet metals. In the original work, the analysis was based on the assumption that the material was rigid-work hardening.

The present work attempts a more rigorous solution, assuming the material to be elastic-work hardening. A finite-element approximation is employed to calculate the stress and strain distribution across the sheet metal annulus at various stages in the deformation process.

A comparison is made between the results from the finite-element method and those based on a rigid-work hardening material. For certain annulus geometries, excellent agreement is obtained between both sets of results.

A new type of automatic balancer which consists of a pair of two-ball balancers to compensate for unbalanced inertia forces and moments is presented. A stability analysis of the balanced condition achievable by such a balancer and the results of a parametric study of its stability are included. Conclusions are drawn regarding the satisfactory operation of the balancer.

The structure of atmospheric turbulence near the ground is reviewed and the statistical properties of the longitudinal, lateral and vertical velocity components of the wind presented. The statistical properties of the turbulence encountered by a high-speed ground transport vehicle travelling through a turbulent wind field of arbitrary orientation are derived. Next, the statistical properties of the atmospheric forces acting on the vehicle are determined and a method of taking account of finite vehicle length is presented. The resulting formulae are applied to a typical tracked hovercraft vehicle.