An Investigation on the Torsional Elastic Wave Theory for the Calculation of Crankshaft Torsional Vibration Response in I. C. Engines

In this paper,a stepped shaft is used as a basic model that is more popular in engineering practice. The partial differential equations of torsional wave propagating along the stepped shaft are set up. The initial conditions,boundary conditions and reflection,transmissions of elastic wave in varying cross-sections are considered. The wave solutions of motion equation are derived in order to determine dynamic response in cross- section of the shaft. Meanwhile,the torsional elastic wave propagation theory is applied for dynamic response investigation of continuous distribution model of shaft system in ship diesel engines. Every order exciting force can be considered in the meantime. Response of forcing vibration in resonance and non-resonance condition can be caculated exactly. The procedure of torsional vibration caculation and measurement is similar.