船用柴油机在台架试验中振动分析与减振优化

摘要

With the development of low-speed two-stroke marine diesel engines in high power and lightweight direc-tion, the transverse vibration of the engines with long or super-long stroke and less cylinders becomes significant. Such a problem becomes considerably serious in rig tests. This article focused on the overlarge vibration of the 5S60ME_C marine diesel engine in the rig test. The transient load of the structural components was computed based on the multi-flexible-body dynamics. A dynamic finite element (FE) model was established and analyzed. Its results were compared with the measure-ment data in the testing. On this basis, the optimal design of the foundation of the test rig was done. The results show that the lateral resonance occurs at the 2nd order modal of H vibration mode, and the resonance can be avoided by adding diagonal braces to the foundation.%随着船用低速二冲程柴油机往大功率、轻量化方向发展，长冲程、超长冲程少缸数的机型横振问题逐渐暴露出来，而在台架试验中该问题尤为突出。针对5S60 ME_C船用柴油机在台架试验中出现的振动超标问题，在柔性多体动力学基础上计算出结构固定件受到的瞬态荷载，利用有限元方法建立模型进行动力学求解，对比试验数据得到准确的分析模型，并在此基础上对台架试验的基础座进行了优化设计。结果表明，柴油机在第2阶H型模态下发生横向共振，通过增加斜向支架能够避免柴油机在指定的测试工况下发生共振。