Analysis Of Vibration-acoustics For300Ton Patrol Vessel In Full-frequency Range

As a kind of small ships sailing near the shore, the patrol vessel is widely used for patrol, guard, detection, search and rescue etc. However, due to the high magnitude and widely spectrum of the vibration sources, the vibration and noise of patrol vessel cannot be effectively analysis used single method likes deterministic methods or statistical methods. So the prediction of vibration-acoustics for the patrol vessel becomes more difficult in full-frequency range. How efficient and accurate predict the noise and vibration in full-frequency range becomes a problem worthy of study.The paper explores the analysis methods of complex systems’ vibration and noise in full-frequency range by a300T patrol vessel. It lays the foundation for the control of vibration and noise for complex structure systems. In accordance with conventional, in the low frequency, FEA can be used to analyze the system’s vibration-acoustics and SEA can be used to analyze the system’s vibration-acoustics in the high frequency. This paper will introduce the middle frequency issue to the vibration-acoustics field and uses FE-SEA hybrid method to analysis complex structure systems’ vibration and noise in middle frequency range. It provides a way for how to analyze the complex structure systems’ vibration and noise in full-frequency range. According to the results, the paper explores how to control the patrol vessel’s cabin noise.Before the completion of the above work, the paper also does the following work. First, the paper discusses the prediction methods of structure vibration in full-frequency range using frame-plate system, and verifies that the FE-SEA hybrid method is reliable in middle frequency range. It provides a theoretical basis for analysis of complex systems’ vibration and noise in full-frequency range. Second, the paper also discusses the feedback control of frame-plate system in middle frequency range by FE-SEA hybrid method.In this paper, based on the segmented modeling ideas, successfully completes the prediction of vibration-acoustics for the patrol vessel in full-frequency range. According to the calculation results can seen that, When calculates the cabin noise level, SEA algorithm is sufficient to meet the precision in practical application, FE-SEA hybrid method is rarely used in cabin noise calculation. When calculates the cabin vibration level, FE-SEA hybrid method calculation results with FEA calculation results agree well in the overlap frequency range, though has a slight error in the prediction of flexible components, but it is still within the acceptable range. This suggests that, FE-SEA hybrid method has the practical value in prediction of the cabin vibration response. From the feedback control numerical results of frame-plate system also can be seen, FE-SEA hybrid method is effective and feasible in structural dynamic response optimization in mid-high frequency range. This indicates that FE-SEA hybrid algorithm is a practical, simple and effective method of calculation and may be widely used in the field of ship vibration-acoustics in future.