... achievable at supercritical speeds relative to the system torsional and lateral modes. However, for counter-rotating rotors, automatic balancing occurs at both subcritical and supercritical speeds relative to the foundation torsional mode. In this investigation, a dimensionless parameter study conducted...

...Ryan J. Monroe; Steven W. Shaw; Alan H. Haddow; Bruce K. Geist Centrifugal pendulum vibration absorbers are used for reducing engine-order torsional vibrations in rotating machines. The most common configuration of these devices utilizes a bifilar suspension in which the absorber mass is suspended...

... for radial, bending, and torsion motions of a flexible drill string and stick-slip interactions between the drill string and an outer shell. Qualitative changes in the system motions are studied with respect to the rotation speed of the drill string and the friction coefficient between the drill string...

...Yukio Ishida; Tsuyoshi Inoue; Tomohiko Fukami; Motohiko Ueda Centrifugal pendulum vibration absorbers (CPVA) have been used for a long time as a method to suppress torsional vibration. Recently, roller type CPVA, that has a similar characteristic but simpler structure, have been investigated...

...M. Moallem This paper presents a wave-based modeling and control approach for suppressing torsional vibrations of an elastic shaft driven by a motor at one end and an inertial load at the other end. A two-port network model representing the dynamics of torsional displacements is obtained starting...

...C. Mei In this paper, wave vibration analysis of axially loaded bending-torsion coupled composite beam structures is presented. It includes the effects of axial force, shear deformation, and rotary inertia; namely, it is for an axially loaded composite Timoshenko beam. The study also includes...

...Yong Chen Presently, the “negative sequence current method” is widely used in field-testing to determine torsional vibration characteristics of steam turbine generator rotor systems. The natural frequencies of lower modes of vibration can be determined effectively in this way, but higher modes...

...A. S. Alsuwaiyan; Steven W. Shaw, Professor, Fellow ASME In this paper we consider the steady-state response of a rotor fitted with a system of nearly identical torsional vibration absorbers. The absorbers are of the centrifugal pendulum type, which provide an effective mean of attenuating...

... of freedom which are radial displacement, rotation of the section considered, bending along the tangential direction and torsion of the string. They include the effects of bending and torsion, the whirling motion of the drillstring as well as friction phenomena occurring between the drillstring and the well...

.... Thomson, W. (Lord Kelvin), and Tait, P. G., 1883, Treatise of Natural Philosophy , Cambridge University Press, London. de Saint-Venant, A., 1855, “De la Torsion des Prismes, avec des conside´rations sur leur Flexion,” Me´moires des Savants E´trangers . Green , A. E. , 1936...