基于扭转弹性波理论的船舶柴油机推进轴系扭振研究

Calculation of crankshaft torsional vibration response in diesel engine by torsional elastic wave theory

本文建立了连续轴模型中沿轴向传播的扭振弹性波的波动方程组,结合方程组的初始条件和边界条件及波动方程解的行波表达式,导出了各轴段扭转弹性波传播的解析表达式,利用数值迭代方法可求解;利用弹性波分析理论对船舶柴油机推进轴系的连续模型进行了扭振响应计算的研究,在激励力上可同时计及各谐次的综合作用,可精确计算共振及非共振工况的强迫振动响应,使计算过程与扭振实测分析过程完全对应。研究中,对某船舶柴油机推进轴系的扭转振动振形和轴系扭振响应进行了计算,获得了较好的效果。

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-section 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 engine.Every order exciting force can be considered in the meantime.Response of the force vibration in resonance and nonresonance condition can be calculated exactly.The processor of torsional vibration calculation and measurement is similar.