Paper 6: On Predicting Crankshaft Stiffnesses and Frequencies

Abstract

Currently design stage calculations of crankshaft stiffnesses involve the extensive use of empirical data. Also, in the calculation of loads on main bearings it is customary to assume the load on any throw to be equally distributed between adjacent main bearings. Before a more realistic approach to the design of crankshafts and main bearings may be made it is necessary to develop and prove a method of analysis. In this paper the finite-element technique is used for predicting the static and vibrational behaviour of crankshafts. The calculated values of axial, torsional, and bending stiffness of a crankshaft, together with its natural frequencies and mode shapes, are compared with experimentally determined values.