a b s t r a c tQuasi-static frictional contact problems for bodies of fairly general profile that can be represented as half planes can be solved using an extension of the methods of Ciavarella and Jäger. Here we consider the tangential traction distributions developed when such systems are subjected to loading that varies periodically in time. It is shown that the system reaches a steady state after the first loading cycle. In this state, part of the contact area (the permanent stick zone) experiences no further slip, whereas other points may experience periods of stick, slip and/or separation. We demonstrate that the extent of the permanent stick zone depends only on the periodic loading cycle and is independent of the initial conditions or of any initial transient loading phase. The exact traction distribution in this zone does depend on these factors, but the resultant of these tractions at any instant in the cycle does not. The tractions and slip velocities at all points outside the permanent stick zone are also independent of initial conditions, confirming an earlier conjecture that the frictional energy dissipation per cycle in such systems depends only on the periodic loading cycle. We also show that these parameters remain unchanged if the loading cycle is changed by a time-independent tangential force, provided this is not so large as to precipitate a period of gross slip (sliding).

Transient heat transfer measurement techniques have long been used in two-dimensional stationary cascade tests designed to model turbine conditions used in Oxford. More recently, experiments studying some of the unsteady effects have been carried out using a rotating wake generator upstream of the rotor cascade. Currently work has concentrated on providing a fully three-dimensional rotating turbine stage. In an associated paper, the modifications necessary to accommodate this stage in the Oxford Isentropic Light Piston Tunnel are discussed. In this paper the developments necessary to permit the measurement of transient heat transfer under these rotating conditions are fully described.