【作者】 范天宇；

【导师】 廖明夫；

【作者基本信息】 西北工业大学 ， 航空宇航推进理论与工程， 2006， 博士

【摘要】 众所周知，阻尼器对于高速旋转机械(如航空发动机)的减振有着重要的意义。不同种类的阻尼器(如挤压油膜阻尼器、金属橡胶阻尼器、橡胶阻尼器等)在实际应用中有着很好的效果。 本文提出了一种新型阻尼器—弹性支承干摩擦阻尼器，它可以用于带有弹性支承旋转机械的减振，其原理为通过两个摩擦片之间的干摩擦为转子提供阻尼。阻尼器的一个摩擦片(动摩擦片)安装在弹性支承的一端，另一个摩擦片(静摩擦片)安装在静子上。如果弹性支承由于转子的振动而产生运动，那么动、静摩擦片之间将产生相对位移，由此产生的干摩擦将消耗振动的能量，从而达到减振的效果。这就是弹支干摩擦阻尼器的工作机理。 干摩擦力取决于作用在摩擦片上的压紧力和动、静摩擦片之间的摩擦系数，摩擦片的表面粗糙度和材料决定了摩擦系数，因此可以通过改变摩擦片压紧力的方法对弹支干摩擦阻尼器进行主动控制。 本文的主要工作及结论如下： 提出了弹性支承干摩擦阻尼器的结构方案，设计制造了弹支干摩擦阻尼器实验器。利用实验器进行了大量的稳态实验和暂态实验，以此研究了干摩擦阻尼器的可行性和有效性。 对转子稳态数据、暂态实验的减速Bode图分析表明，弹支干摩擦阻尼器可以有效地抑制由转子不平衡而引起的振动。暂态实验数据还表明，干摩擦阻尼器能够大大降低转子通过临界转速时的振动峰值，这对于柔性转子的正常工作有着重要的意义。 建立了转子—弹性支承—干摩擦阻尼器系统中转子的运动微分方程，采用库仑摩擦模型描述摩擦力。从理论上分析了弹支干摩擦阻尼器的减振机理，并证明了弹支干摩擦阻尼器可以用于转子系统的减振和镇定。运用能量平衡法确定了带有干摩擦阻尼器的转子的镇定边界。 采用滞迟弹簧模型描述干摩擦力，运用Fourier级数展开法和谐波平衡法简化双折线本构关系，建立了转子—弹性支承—干摩擦阻尼器系统一自由度及二自由度力学简化模型，计算了系统的振动响应特性。 采用Fourier级数展开法、增量谐波平衡法、精细积分法求解转子—弹性支承—干摩擦阻尼器系统一自由度、二自由度理论模型的振动响应，计算结果表明三种方法均可准确地得到系统的振动响应，其结果略有差异，可以忽略。 通过与数值积分方法计算结果对比，验证了Fourier级数展开法的准确性。在二自由度模型求解中，运用拟牛顿法来求解非线性方程组，给出了相应的公式更多还原

【Abstract】 It is well known, damper is an important component reducing vibrations in rotating machines running at high speed, for example in aero-engines. In different types of dampers such as squeeze oil film dampers, metal rubber dampers and rubber dampers have found successful applications.In this paper, a new type of damper-elastic support/dry friction is designed to suppress vibrations in rotating machines. It provides a rotor with damping by friction or two disks. One disk is fixed on the end cross section or elastic support and another one is placed in a fixed support. If the support moves, due to rotor vibration, then a relative motion between the support and the disk will occur. This will lead to a dry friction dissipating the vibration energy. The friction damper works in this principle.The dry friction force depends upon the force pressing the disk on the end cross section of the support and the friction coefficient associated with surface roughness and materials. Hence the damper can actively be controlled by changing the pressing force.The main works and conclusions are the following:The structural of elastic support/dry friction damper is introduced. A test rig is designed and set up to examine the feasibility and effectiveness of elastic support dry friction damper. The experiments include the steady state and the transient condition.The data of steady state and Bode diagram of transient condition show elastic support dry friction damper can reduce the vibration from rotating unbalance. The data of Bode diagram prove the dry friction damper can reduce the peak amplitude of vibration at critical speed.Coulomb dry friction model is used. The differential equations of rotor- elastic support-dry friction damper system are given. The results show that elastic support/dry friction damper can stabilize and reduce the vibration of rotor system. It is shown in theoretical analysis that elastic support dry friction damper can stabilize the free vibration of rotor. A boundary limit of the stabilization provided by the dry friction damper is obtained.In the hysteretic dry friction model, the hysteresis curve is simplified by Fourier method and harmonic balance method. The vibration responses are calculated to single degree of freedom model and two degree of freedom model of rotor- elastic support- dry friction damper system.更多还原