磁流变弹性体舰船推进轴系纵振吸振器的设计与实验

发布时间：2018-05-18 05:15

本文选题：舰船推进轴系 + 磁流变弹性体　；参考：《上海交通大学》2015年硕士论文

【摘要】：螺旋桨是舰船主要的动力推进机构,其旋转运动产生的轴向作用力驱动舰船的航行。同时,其旋转运动会在舰船的艉部引起不均匀的伴流场,将会对螺旋桨形成脉动冲击,并经轴系、轴承、支撑结构等传递到舰船壳体,诱发船体的振动。对于水面舰船而言,脉动推力产生的振动会影响其乘坐的舒适性,同时对船体中的设备造成危害;对水下舰艇而言,螺旋桨脉动推力造成船体振动产生的辐射噪声是其船体辐射噪声的主要来源,大大降低了水下舰艇的声隐身性能。因此,研究螺旋桨脉动推力在舰船推进轴系中的传递规律,并结合舰船轴系纵向振动的动力学分析,是舰船减振降噪的关键。磁流变材料是一种合成智能材料,其显著的特点是其流变性能。磁流变弹性体(MREs)以橡胶为基体,将微米级的尺寸铁、钴、镍等金属软磁材料分散于基体中,形成具有流变特性的智能橡胶材料。在外加磁场的作用下,它的力学属性(如杨氏模量、剪切模量)能发生瞬时、连续、可逆的变化,并且能够方便的进行调整和控制。因此,磁流变弹性体被广泛应用到可调谐式减振器的设计之中。本课题针对舰船轴系纵向振动控制展开研究,结合智能材料磁流变弹性体微观组织特点和宏观力学性能,设计出一款结构新颖、适用领域宽广的磁流变弹性体半主动动力吸振器(MREs-DVA)。通过应用磁流变弹性体的剪切模量可控的特性获得减振频带范围可调的半主动式动力吸振器,实现变转速工况下对舰船轴系纵向振动的有效控制。主要工作内容有:(1)建立舰船推进轴系—动力吸振器综合动力学模型,并提出磁流变弹性体半主动式吸振器设计思路,;(2)磁流变半主动式舰船轴系动力吸振器结构设计与加工;(3)动力吸振器单体移频性能、温度变化规律实验验证与数据分析;(4)组合式动力吸振器宽频振动控制性能实验验证与数据分析。通过以上这些工作,验证了利用磁流变弹性体力学性能可调的特点设计动力吸振器的构想,得到了明显的移频效果与良好的宽频振动控制性能,从而为舰船推进轴系的纵向振动控制课题探索出有益的借鉴、理论和工程依据。
[Abstract]:Propeller is the main propulsion mechanism of a ship. The axial force produced by its rotating motion drives the ship's navigation. At the same time, the rotating motion of the ship will cause an uneven wake flow field in the stern of the ship, which will form a pulsating impact on the propeller and be transmitted to the hull of the ship through shafting, bearing and supporting structure, which will induce the vibration of the ship's hull. For a surface ship, the vibration caused by pulsating thrust will affect its ride comfort and cause harm to the equipment in the hull, while for the underwater ship, the vibration will affect the comfort of the ship's ride and cause harm to the equipment in the ship's hull. The radiated noise caused by the pulsating thrust of the propeller is the main source of the radiated noise of the ship, which greatly reduces the acoustic stealth performance of the underwater ship. Therefore, the key to reduce vibration and noise is to study the transfer law of propeller pulsating thrust in ship propulsion shafting, and to combine with the dynamic analysis of ship shaft longitudinal vibration. Magnetorheological material is a kind of synthetic intelligent material, its remarkable characteristic is its rheological property. The magneto-rheological elastomer (MREs) is based on rubber. The soft magnetic materials, such as iron, cobalt, nickel and so on, are dispersed in the matrix to form intelligent rubber materials with rheological properties. Under the action of external magnetic field, its mechanical properties (such as Young's modulus, shear modulus) can be instantaneous, continuous, reversible changes, and can be easily adjusted and controlled. Therefore, magnetorheological elastomers are widely used in the design of tunable shock absorbers. In this paper, the longitudinal vibration control of ship shafting is studied, and a novel structure is designed according to the microstructure characteristics and macroscopic mechanical properties of the smart material magneto-rheological elastomer. MRES-DVA is a wide range of magnetorheological elastomer semi-active vibration absorbers. By applying the controllable shear modulus of magneto-rheological elastomer, a semi-active dynamic vibration absorber with adjustable frequency band is obtained, which can effectively control the longitudinal vibration of ship shafting under variable rotational speed. The main contents of the work are as follows: (1) to establish a comprehensive dynamic model of ship propulsion shafting and dynamic vibration absorber. The design idea of semi-active vibration absorber of magnetorheological elastomer is put forward. (2) the structure design and processing of dynamic vibration absorber of magnetorheological semi-active ship shafting are presented. Experimental verification and data analysis of temperature variation rule. (4) Experimental verification and data analysis of broadband vibration control performance of combined dynamic vibration absorber. Through the above work, the idea of designing dynamic vibration absorber based on the adjustable mechanical properties of magneto-rheological elastomer is verified, and the obvious effect of frequency shift and the good control performance of wideband vibration are obtained. Thus, it provides useful reference, theory and engineering basis for the longitudinal vibration control of ship propulsion shafting.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U664.21

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