Results 261 to 270 of about 24,495 (308)

Self-excited vibrations of a drillstring bit

International Applied Mechanics, 2013
The whirling vibrations of a rotating drillstring bottom-hole assembly subject to the moment of friction are analyzed qualitatively. A problem statement and solution are given. The self-excitation of vibrations is simulated. It is established that during the self-excitation of whirling vibrations, the axial line of the drill bit can slowly and rapidly ...
V. I. Gulyaev, P. Z. Lugovoi, E. I. Borshch   +2 more
openaire   +1 more source

Quenching of self-excited vibrations equilibrium aspects

Journal of Sound and Vibration, 1975
Abstract An analysis is presented of two types of self-excited, two-degree-of-freedom systems. The basic subsystem, in each, is governed by a Van der Pol differential equation. This subsystem is considered attached to a vibration absorber or mounted on a resilient foundation.
openaire   +1 more source

Analysis Of Self-excited Longitudinal Vibration Of A Moving Tape

Journal of Sound and Vibration, 1993
Abstract Longitudinal vibration of a moving magnetic tape can be excited by frictional contact with a recording head, or with a guide that defines the path of the tape. The friction force depends on the velocity, relative to a stationary observer, of the tape element that is instantaneously located at the point of contact.
openaire   +1 more source

On the self-excited chatter vibration in motorcycles

2023
This study is focused on the understanding of the nonlinear effects of tyre forces and chain geometry on motorcycle chatter, a self-excited oscillation arising at the rear wheel during heavy braking manoeuvres. In particular the post-bifurcation criticality is assessed, whether subcritical or supercritical, with respect to travelling speed.
Alexander Schramm, Silvio Sorrentino, Alessandro De Felice   +2 more
openaire   +1 more source

Self-Excited Vibration of a Hydraulic Turbine

Journal of Engineering for Power, 1967
Severe vibration of a hydraulic turbine was found to be self-excited. Vibration at the natural frequency when operating at synchronous speed produced self-sustaining whirl of the shaft. Gyroscopic action of the turbine runner caused the vibration to be self-excited.
C. C. Crawford, F. O. Ruud
openaire   +1 more source

Self-excited vibrations of turbomachine blading

Zeitschrift für angewandte Mathematik und Physik ZAMP, 1964
Unter Verwendung einer vereinfachten Betrachtungsweise fur die nicht-stationaren aerodynamischen Krafte wird ein Kriterium fur das Zustandekommen von selbst-erregten Schwingungen bei Axialturbinen- bzw. Axialkompressoren-Schaufeln angegeben, die entlang ihrer Hohe sowohl aerodynamisch wie auch geometrisch veranderliche Eigenschaften aufweisen.
openaire   +2 more sources

On Self-Excited Friction Vibrations in Brakes

Volume 3A: 15th Biennial Conference on Mechanical Vibration and Noise — Vibration of Nonlinear, Random, and Time-Varying Systems, 1995
Abstract Dynamic processes in machines resulting from the interaction between rough rubbing surfaces are called self-excited friction vibrations in the theory of vibrations. Such vibrations are generated in machines brakes, causing the instability of then-operation and various noise effects.
Fedor R. Gekker, Serik I. Khairaliev
openaire   +1 more source

Differential evolution for system identification of self-excited vibrations

Journal of Computational Science, 2015
This study uses a differential evolution method to identify the coefficients of second-order differential equations of self-excited vibrations from a time signal. The motivation is found in the frequent occurrence of this vibration type in physics and engineering. In the proposed method, an equation structure is assumed at the level of the differential
Christiaan D. Erdbrink, Valeria V. Krzhizhanovskaya   +1 more
openaire   +2 more sources

Design of a Screw Jack Mechanism to Avoid Self-excited Vibrations

Journal of Dynamic Systems, Measurement, and Control, 2002
This paper deals with vibratory phenomena that are encountered in screw jack mechanisms, down-motion especially. One can find many practical instances where such mechanisms are subject to vibratory conditions. Besides producing loud noise, vibrations can easily damage the mechanism.
GALLINA, PAOLO, GIOVAGNONI M.
openaire   +3 more sources

Self-Excited Vibrations in Metal Cutting

Journal of Engineering for Industry, 1959
The basic mechanisms which cause self-excited vibrations of a cutting tool relative to the work are discussed in a qualitative manner. Similarly, mechanisms inherent in the cutting process which can damp or limit vibrations are discussed. Experiments are presented which are in agreement with the theory.
openaire   +1 more source