【作者】 邱飞宇；

【导师】 孙保苍；

【作者基本信息】 江苏大学 ， 结构工程， 2006， 硕士

【摘要】 随着科学技术的进步，旋转机械正日益向着高速、高效方向发展，对其动力特性、稳定性以及可靠性也提出了更高的要求。现代非线性动力学理论的发展与运用，使得转子动力学研究面貌一新，并且已成为当今国内外的热门研究课题。 旋转机械中常常会出现两种或两种以上故障同时存在的情况，其耦合故障的非线性动力学行为较单一故障更加复杂，且相互影响。本文以现代非线性动力学理论和转子动力学理论为基础，采用新的短轴承非稳态非线性油膜力公式和非稳态油膜转子—轴承系统碰摩的刚性约束非光滑模型，利用数值积分方法研究了油膜力作用下碰摩转子系统的非线性动力学行为，并且作出了系统响应的相图、Poincare截面图、幅值谱图、分岔图和时序响应图，分析了系统响应随转速、不平衡量和油膜特性参数等变化而出现的复杂的非线性动力学现象，研究结果表明：随着转速增加，碰摩力逐渐成为系统响应的主要因素；随着偏心量增加，系统响应出现丰富的非线性现象；定子刚度对转子系统有较大的影响。 其次，对含松动与碰摩的转子系统的非线性动力学行为进行了详细的分析，考察了其随转速、轴承支座质量以及偏心量等变化的非线性动力学特性，得到如下结论：转速较低时，未松动端转轴中心以及松动端轴承支座作微幅振动；在高速运转中，轴承支座质量越大，转子系统稳定性越好；转子系统中松动端轴承支座在拟周期和混沌运动状态下的轴心轨迹呈“柱状”结构。 第三，针对工程实际中的转子—轴承系统是一个复杂的具有局部非线性的多自由度动力系统，初步探讨了模态综合技术。采用改进的自由界面模态综合法，将线性自由度变换到模态坐标中进行缩减，而非线性自由度仍然保留在物理空间，从而大幅度地减小系统的线性自由度，并且使降阶后的系统仍具有局部非线性特征。 最后，总结了本文所做的主要工作，同时指出了存在的问题以及今后工作的发展趋势。更多还原

【Abstract】 Along with the progress of science and technology, the rotating machinery has been developed to higher speed and efficiency. And a lot of higher requirements for dynamic characteristics, stability and reliability to the rotating machinery have been made. With the development of the modern nonlinear dynamic theory, the research on rotor dynamics takes a new visage after introducing the theory of modern nonlinear dynamics. Nowadays, it has been become a pop research problem at home and abroad.In the rotating machinery, two or upwards two kinds of faults are often concurrent. The nonlinear dynamic behaviors induced by coupled faults are more complex than those induced by singular fault, and the faults are influenced with each other. This paper bases on the theory of modern nonlinear dynamics and the theory of rotor dynamics, adopting a new unsteady and nonlinear oil-film force model and a non-lubricious rigid restricted model of the unsteady oil-film rotor-bearing system. Using the method of numerical integration, this paper researches the dynamic behaviors of the nonlinear system under the coupled faults of the oil-film force, colliding and rubbing, and works out the phase diagrams, Poincare maps, spectrum analysis diagrams, bifurcation diagrams and time sequence response diagrams of the system. And this paper analyses the complex nonlinear dynamic phenomena of the system along with the change of the rotating speed, imbalance quantum and the characteristic parameter of the oil-film, and obtains conclusions as follows: the force of colliding and rubbing is becoming the main infected factor to the response of the system along with the increase of rotating speed; many abundant nonlinear phenomena appear in the response of the system along with the increase of eccentric quantum; the degree of rigidity of the stator has large influence to the rotor system.Secondly, a detailed analysis has been made to the nonlinear dynamic behaviors of the rotor system having the faults of the flexible support, colliding and rubbing. Seeing about the nonlinear dynamic characteristics along with the change of rotating更多还原