海洋平台主机舱振动建模仿真分析及试验研究

Simulation modeling and experimental analysis on vibration of offshore platform engine cabin

为了优化结构整体减振性能,以某海洋平台主机舱为研究对象,利用典型运行工况下平台的振动试验实测数据对主机舱柴发机组引起的结构振动传递进行仿真分析,建立不同的主机舱振动计算模型,比较不同边界条件、不同隔振器刚度对计算结果的影响,提出适用于工程实用的较为精确的主机舱整体有限元仿真模型。通过计算推进器40%功率状态和航行状态2种典型运行工况下主机激励经由机脚、隔振器传递到平台基座的振动传递,并与实船测试结果进行比较,验证了有限元分析模型的合理性和精确性,计算结果可靠,具有较高的工程价值,为后续海洋平台主机舱隔振优化设计提供参考。

In order to meet the need for improving vibration and noise isolation performances,a FEM model was estab-lished for the complex system composed of platform cabin,machines and isolators to analyze the vibration transmission from the machine to the isolators and to the foundation of the whole cabin structure.Discussions were presented for influences of five different models with different boundary conditions and isolator stiffnesses.Excitation experiments for the platform en-gine cabin with two different working conditions,ie.,40%power and sailing,were performed.The vibration responses from the excitation points to the vibration points were obtained.The finite element calculation results were compared with the ex-perimental results.The two results were relatively close with each other which indicated that for the low frequency band,it's improper to simulate the dynamic characteristics with one cabin model.The FEM model of the engine cabin can meet the need for engineering applications and can also provide some useful reference for isolation optimization design of the off-shore platform.