复合螺旋管弹性联轴器强度寿命分析与结构改进

发布时间：2017-12-31 14:16

本文关键词：复合螺旋管弹性联轴器强度寿命分析与结构改进　出处：《南京航空航天大学》2011年硕士论文　论文类型：学位论文

【摘要】：弹性联轴器应用十分广泛。无论是在航空还是在其它领域,弹性联轴器都有十分重要的应用价值。本文研究的多层结构的复合螺旋管弹性联轴器具有尺寸小、传递功率大、寿命长等特点。本文针对其结构特点,首先采用理论和有限元方法针对单层螺旋管的扭转刚度和强度进行了分析,然后采用接触非线性有限元方法,对复合螺旋管弹性联轴器不同受载条件下的扭转变形、刚度、强度等进行了详细分析。得到以下研究结果: 1.建立了接触非线性有限元计算模型,详细分析研究了联轴器扭转刚度的非线性特性。研究结果表明:联轴器的扭转刚度与受载密切相关,初始阶段为线性特性,随着载荷增加,其刚度表现为阶段性线性增加,其原因与联轴器结构形式相关;同时刚度也受到转速变化的影响,其原因是离心力影响联轴器的接触应力。 2.动载荷作用下,当频率比小于1时,联轴器等效刚度随频率比的增大而减小,当频率比大于1时,随着频率比的增加,等效刚度逐渐增大。在某一轴系中,为使联轴器起减振作用,要求动力放大系数Km小于1,对应最小激励频率随着刚度的增加而增加,增加趋势逐渐放缓。在阶跃载荷作用下,联轴器传递的总扭矩的最大值不变。脉冲载荷作用下,为使联轴器起减振作用,激励扭矩的最大脉冲时间随刚度的增大而减小,减小趋势逐渐放缓。 3.由于非线性接触的影响,随着扭矩的增加,联轴器最大应力增加速度逐渐变缓;一定转速范围内,随着转速的增加,联轴器的最大应力逐渐变小;扭矩较小时径向偏转对联轴器的最大应力影响不大,当扭矩足够大时,联轴器径向补偿能力减弱。 4.通过基于应力确定寿命的方法,使用多种非对称应力循环等效方法,根据不同疲劳损伤理论,对联轴器的疲劳寿命进行计算分析,并对得到的结果进行对比分析。为联轴器的使用和改进提供了依据。 5.对联轴器进行结构上的改进,得到一种新式复合螺旋管弹性联轴器,使其相同扭矩下的最大应力相对于改进之前降低27%左右,并且结构重量也降低了14.82%。本文的研究对于弹性联轴器发展具有重要的促进意义。
[Abstract]:Elastic coupling is widely used in aviation and other fields. Elastic coupling has a very important application value. The multi-layer composite spiral tube elastic coupling studied in this paper has a small size. According to the characteristics of its structure, the torsional stiffness and strength of single-layer spiral tube are analyzed by using theory and finite element method. Then the contact nonlinear finite element method is used to analyze the torsional deformation, stiffness and strength of the elastic coupling under different loads. The following results are obtained: 1. The contact nonlinear finite element model is established, and the nonlinear characteristics of the coupling torsional stiffness are analyzed in detail. The results show that the coupling torsional stiffness is closely related to the load. At the initial stage, the stiffness of the coupling increases linearly with the increase of load, and the reason is related to the structure of the coupling. At the same time, the stiffness is also affected by the change of rotational speed, which is due to the influence of centrifugal force on the contact stress of the coupling. 2. Under dynamic load, when the frequency ratio is less than 1:00, the equivalent stiffness of the coupling decreases with the increase of the frequency ratio, when the frequency ratio is greater than 1:00, with the increase of the frequency ratio. In order to reduce the vibration of the coupling, the dynamic magnification factor (km) is required to be less than 1, and the corresponding minimum excitation frequency increases with the increase of stiffness. Under the action of step load, the maximum value of the total torque transmitted by the coupling is not changed. Under the action of pulse load, the vibration of the coupling is reduced. The maximum pulse time of excitation torque decreases with the increase of stiffness, and the decreasing trend gradually slows down. 3. Due to the influence of nonlinear contact, with the increase of torque, the increasing speed of maximum stress of coupling becomes slower. In a certain speed range, the maximum stress of the coupling becomes smaller with the increase of the speed. When the torque is small, the radial deflection has little effect on the maximum stress of the coupling. When the torque is large enough, the radial compensation ability of the coupling weakens. 4. The fatigue life of the coupling is calculated and analyzed according to different fatigue damage theory by the method of determining life based on stress and using many kinds of equivalent methods of asymmetric stress cycle. The results obtained are compared and analyzed, which provides the basis for the use and improvement of the coupling. 5. By improving the structure of the coupling, a new type of composite spiral tube elastic coupling is obtained, which reduces the maximum stress under the same torque by about 27%. And the weight of the structure is also reduced by 14.82. The research in this paper is of great significance to the development of elastic coupling.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH133.4

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