Study of Torsional Vibrations of Turbomachine Shafts: Part 1. Algorithm Optimization for the Determination of the Parameters of Natural and Forced Torsional Vibrations of Shafts

Torsional Vibration Analysis Using Rotational Laser Vibrometers

“…From a physical point of view, the considered test rig has very low damping levels, the mail components (ball bearings, mechanical transmission, and couplings) were selected to be fully rigid, and the resulting system is stiff. The low damping level is also confirmed in the existing literature, and it is usually considered an issue for real rotating machines [6,19,20]. Moreover, the estimation of the system damping is an important aspect when calculating the torsional stress in the shaft line and fatigue assessment.…”

“…Torsional vibrations are critical for various engineering fields, such as power production plants [ 2 , 3 ]. Typical examples of sources of torsional vibration are: Electric motor/generator defects due to electric imbalances and short circuit defects [ 4 ]; Pump, compressor, turbine, and fan defects cause torsional excitations at an equal or multiples of the blade passing frequency [ 5 , 6 ]; Gear drives, where elastic deformation and defective tooth surfaces can cause torsional oscillation; Cardan joints in which the driven shaft is submitted to an oscillation of doubled frequency with respect to the drive one. …”

“…Pump, compressor, turbine, and fan defects cause torsional excitations at an equal or multiples of the blade passing frequency [ 5 , 6 ];…”

“…In the existing literature, the torsional vibration analysis of real rotating machines is a common assessment procedure. It is used for both the monitoring of faulty machines [ 6 , 19 , 20 ] and the design of innovative torsional dampers to be applied on long shafts lines [ 21 , 22 ]. Usually strain gauges and phonic wheels are used for experimental measurements [ 23 , 24 ], but they require an invasive and dedicated set-up.…”