【作者】 焦灵芝；

【导师】 陈照波；

【作者基本信息】 哈尔滨工业大学 ， 机械设计及理论， 2009， 硕士

【摘要】 军用舰船的隐身性是衡量舰船性能的主要指标,直接影响其攻击能力和防御的能力。舰船的声隐身性主要取决于舰船辐射的噪声。研究表明舰船噪声主要由船上设备的振动产生。舰船的回转机械在运转时产生振动,这种振动通过设备基座传到甲板,引起整船的振动,从而产生噪音,破坏舰船的隐身性。因此对基座进行隔振,能有效降低舰船的噪声,提高舰船的声隐身性。目前,国内对机械设备的振动影响控制采取的主要手段是采用隔振设备,利用隔振器的设计降低振动传递率。但阻尼减振已成为前沿课题。本文讨论采用敷设阻尼的方法对舰上典型设备基座进行减振降噪控制的研究。本文根据实际基座结构通过有限元方法建立模型,并通过模态计算及静力学分析计算确定基座-甲板的等效结构尺寸。设计出基座-甲板结构,使该实验结构能够反映出设备基座真实的工作状态及振动模态。利用该实验结构进行基座无阻尼结构频响函数测试,并将测试的响应结果与有限元谐响应计算结果做对比,根据固有频率及振动幅值的不同,修正有限元结构的参数,确定与实验结构刚度等相符合有限元模型,用于后期有限元仿真计算。从分析阻尼结构的减振机理入手,研究了自由阻尼、约束阻尼的减振机理及对其减振效果的影响因素。研究了阻尼敷设在悬臂梁结构时,其结构参数对减振效果的主要影响,并以此为基础,根据模态应变能理论,通过有限元方法仿真不同的阻尼形式、阻尼厚度比、阻尼弹性模量比及阻尼的敷设位置等对该舰用设备基座等效结构的阻尼减振效果的影响。为了验证阻尼减振效果,利用实验基座结构分别测试无阻尼结构、自由阻尼结构、约束阻尼结构及局部阻尼等情况下的频响函数。通过对实验结果的对比分析得出当敷设不同阻尼结构后在相同输入激振力下,其输出响应要小于不敷设阻尼的情况,尤其在中高频段其减振效果尤为明显。通过理论分析和实验对比分析可以看出当采用阻尼结构进行减振时,其减振效果良好,并且阻尼减振结构附加质量小,适用于航天、航海领域。更多还原

【Abstract】 Acoustic Stealth is an important indicator to ships.Mechanical vibration is the main source of the noise on ship when the equipments are on work. If the noise of the structure radiates into the air, it will become air noise , if it radiates into the water ,it will come into being the underwater noise, which will let the performance of the noise stealth down.This kind of vibration will make people discomfortable in particular to the civilian vessels and it will make damage to the people who work on the ship. In addition, acceleration generated by the vibration may make the precision equipments lose effectiveness.To military ships, the vibration and noise caused by the rotating equipment will lead to the self-betrayal and make themselves to be attacked.At present , The main means of Controlling the influence of vibration is using Isolation equipment internal.However, damping vibration attenuation has became frontier research topic.They can let the transmissibility down by designing the structure of isolation equipment.In this paper, I will make it by laying damping. A finite elements model is built according to the base.The structure of base-deck is determined after model analysis and statics analysis in ANSYS .the equivalent model needs to reflect the real condition.Take the frequency response measurement and compare with simulation results, the parameters is modified according to the differences of the frequence and amplitude.At last ,a model is set up which is used to later calculation.Research on the mechanism of vibration reduction of free damping and constrained damping. Find out which structural parameters of the damping play the most important role to loss factor.Do calculation by finite element method to study on how to set the parameters the structure can get the most effective effect on controlling the vibration.Testing the vibration acceleration signals when the structure is laid by different laying type,different thickness of damping and different location of damping .We can get the result by comparing the data of the experiments that after laying damping ,the response is released which proved that the vibration is controlled.Damping structure adds small mass to the basement and the effect of controlling vibration is significant.In a word,the damping structure is applicable to space field and navigation field.更多还原