Experimental Investigation of a System With Multiple Nearly Identical Centrifugal Pendulum Vibration Absorbers

Abstract

This paper presents experimental results from tests completed on a rotor system fitted with nearly-identical circular path centrifugal pendulum vibration absorbers. A brief review of theoretical background for the absorbers is given along with an overview of the test apparatus. The experimental results for one absorber and for four absorbers are presented and compared with theoretical predictions and expectations. To the best knowledge of the authors, this is the first time that systematic, controlled experiments that monitored both the response of the absorbers and the rotor have been undertaken.

Nonlinear Transient Dynamics of Pendulum Torsional Vibration Absorbers—Part II: Experimental Results

“…The absorbers used in this study have been used previously for studies of steady state responses, which considered single and multiabsorber systems, and were used to validate perturbation analytical results for general path absorbers [2][3][4] and near tautochronic path absorbers [5]. Previous studies considering the transient dynamics of pendulum vibration absorbers include simulations for circular path absorbers [6] and analytical closed-form results for damped linear absorbers [7], which closely approximate the results for near tautochronic absorbers.…”

“…where r is the radius of gyration of the circular path absorber about its COM (see Nester et al [2] for details). Note that these parameters arise from the single point suspension of the absorber and b ¼ 1 and a ¼ 0 for all absorbers with bifilar suspensions, regardless of the path.…”

“…1. This basic setup was previously described and characterized in works that considered steady state absorber responses [2,3,5,8]. Since those studies, the rig was upgraded with a new servo motor (C) and controller (B) and has undergone significant software updates for motor control, response readouts, and data processing.…”

“…2(b) is a circular path pendulum type absorber suspended at a single pivot point, as considered in Ref. [2]. In contrast to the near tautochronic absorber, the circular path absorber is a compound pendulum absorber suspended by a pin and needle bearing.…”

“…The parameters taken to be fixed for each absorber type include the absorber equivalent viscous damping coefficient l, the absorber tuning order ñ, the absorber path nonlinearity given by k and/or j, and the absorber/rotor inertia ratio . Only a brief summary of how each system parameter is estimated is given, since these methods are abstracted from previous works [2,3,5,8]. An error analysis in regards to the uncertainty in the estimated system parameters is performed following the NIST Type A method [11].…”