Design of shaft mounted
Shaft mounted are used in all kinds of machinery and mechanical.Although for a circular shaft mounted with static torsional loads is useful,most shaft mounted are subjected to fluctuating loads of combined bending and torsion with various degree of stress concentration.For such shaft mounted the problem is fundamentally one of fatigue loading.In addition to the shaft itself,the design usually must include the calculation of the necessary keys and couplings.The normal operating speed of a shaft should not be close to a critical speed, or large vibrations are likely to develop.In this chapter, equations are given for finding the deflections of shafts of nonuniform diameters.
Torsion of circular shaft mounted
A circular shaft of uniform cross section loaded at the ends by the torques T, Which twist it about the longitudinal axis.The shaft mounted is assumed to be much longer with respect to the diameter than is indicated by the figure.It can be shown experimentally that cross sections perpendicular to the axis before loading remain plane and perpendicular to the axis after the loads T have been applied.The diameter of the bar is unchanged, and radial lines remain straight and radial after twisting.
Design of shaft mounted for fluctuating loads
Even a static moment applied to a shaft will give rise to a cyclic load because the shaft mounted rotates,creating a situation of completely bending.The most frequently encountered stress situation for a transmission shaft mounted is to have bending and steady or nearly steady torsional stress.Another ,less frequently encountered, stress situation is the case for bending in combination with torsion.Both of these loading situations call for design equations that allow us to handle multiaxial fatigue.The approach that is most frequently applied to handle these situations is to replace the dynamic stress patterns by equivalent static stress patterns,combine the static stresses using conventional means, and then to apply a failure based on these static stresses.