某军用发动机振动模态的实验研究与计算

Experiment and Calculation of Vibration Modal of a Military Engine

为了研究军用发动机整机结构的动力学特性,在各子结构——机体、曲轴、缸盖和曲轴箱三维实体模型的基础上,组装成整机模型。采用实验研究和理论计算相结合的方法,对此整机的振动模态进行了研究。由于部件间结合面的刚度与阻尼特性难于理论分析和实验提取,采用了虚拟材料来模拟结合面特性,通过反复修正虚拟材料的特性常数,使得整机有限元振动模态分析结果与实验结果吻合。从而说明所建立的整机的有限元模型是正确可靠的,为整机结构进一步的动态仿真研究奠定了基础。

To research the dynamic properties of military engines, experiment analysis and finite element calculation were adopted. Based on the correct 3-D solid models of body, crankshaft, cylinder head and crankcase, an integrated engine model was built in this paper. Virtual materials were introduced to simulate the stiffness and damping features of the joint surfaces between those four elements, which are difficult to obtain either theoretically or experimentally. Property parameters of the virtual materials were gradualy modified until FEM result of the engine＇s vibration modal became consistent with the experiment result. Thus, the validity of the finite element model of the engine was proved, which paves the way for further engine dynamic simulation research.