Mathematical Modeling and Experimental Results of the Dynamic Response of a Misaligned Rotor System

作者：Taraboulsi Gabriel^*; Ahmed A K W; Kaushal A

来源：Advances in Vibration Engineering, 2011, 10(1): 63-77.

• Angular misalignment
• Axial misalignment
• 1x
• 2x
• Simple rotor

Misalignment is one of the major causes of machinery vibration in the field yet only limited research has been conducted on misalignment. The literature reports that misalignment results in an increase in the vibration at a frequency 2x (x: speed of rotation). The research conducted so far has modeled rotor, with two coupled shafts supported on linear and nonlinear bearings. The results reported to date are inconsistent, in some cases showing the existence of 2x and in some cases the 2x was not observed, and the increase in 2x component is some time attributed to nonlinear properties. This paper presents a study on the effects of shaft misalignment on the dynamic response of a rotor-shaft system. A simple rotor system supported on two rigid bearings is modeled using the energy method, and Lagrange is used to establish the equations of motion. Bearing and coupling are not modeled in this paper to emphasize the effect of a nonlinear stiffness on the rotor response. A response due to perfectly aligned case is compared with those for parallel and angular misalignments of various magnitudes. Simulations are carried out for a speed range of 0 to 8,000 rpm, and the response of the rotor at the 2x is examined to establish the effects of various misalignment parameters on the response. Limited experiments are conducted using a rig test to confirm the vibration pattern predicted by the simulations. Such behavior can be used in developing tools for reliable diagnosis of misalignment in a rotating system.

• 出版日期2011-3