Guards on machine tools are meant to protect operators from injuries caused by tools, workpieces, and fragments hurled out of the machine's working zone. This article presents the impact resistance requirements, which guards according to European safety standards for machine tools must satisfy. Based upon these standards the impact resistance of different guard materials was determined using cy...

One source of structural vibration in a submarine is the fluctuating axial thrust force applied to the thrust block by the propeller shaft. This paper describes the initial stages of experimental work being undertaken to validate an existing mathematical model for the sound radiation from a submarine excited by this mechanism. A thin cylindrical shell 1500mm long and 400mm in diameter made of 2...

When a thick cylindrical coin is tossed in the air and lands without bouncing on an inelastic substrate, it ends up on its face or its side. We account for the rigid body dynamics of spin and precession and calculate the probability distribution of heads, tails, and sides for a thick coin as a function of its dimensions and the distribution of its initial conditions. Our theory yields a simple ...