内燃机轴系扭转—纵向耦合振动数学模型

The Mathematical Model for the Coupled Torsional-Axial Vibration of Internal Combustion Engine Shaft System

本文提出了一种具有非线性刚度的弹簧一质量模型,用于计算内燃机轴系的扭转—纵向耦合振动。以单曲柄为例,对(1)仅有扭转激励力矩,(2)仅有轴向激励力,(3)两种激励力同时存在的三种情形分别作了分析计算,证明了该模型的可行性。对单曲柄和双曲柄系统的仿真算例和谱分析结果给予了进一步的论证。最后,本文还将该模型推广至更符合实际的多自由度系统。

This paper presents a new mathematical model for calculating the coupled torsional-axial vibration with non-linear stiffness for a lumped spring-mass shaft system of internal combustion engine. As an example for the single crank shaft system, the following three exciting conditions are calculated and analysed: i)torsional exciting torque only; ii) axial exciting force only, and iii)two exciting forces simultaneous. The calculated results demonstrated that the model is applicable. Finally, the mathematical model is extended to a multi-degree of freedom system of actual shafting system, and a digital simulating calculation with its spectrum analysis gives supports to this model.