Behaviour of multilayer stacks of thin layers under dynamic loads

Abstract

Although considerable attention has been given to solids in static contact, very little information is available concerning vibrated contacts. Stacks of thin metallic layers were subjected to high and low dynamic loads (⩽ 156 + 1290 sin 2 (2800 πt) N, t being in min). Freshly assembled stacks show an initial fall in resistance, (which was not found for run-in stacks), the rate of fall being greater the harder the material. For run-in stacks under high dynamic loads, the asperity tips tended to shear, resulting in a resistance rise, while under low dynamic loads the asperities tended to deform so that the resistance decreased. Also under low dynamic loads, an exponential rate of fall of the electrical resistance of stacks of thin layers of soft material has been observed.