Nonlinear Steady-State Vibration Analysis of a Beam with Breathing Cracks

Abstract The authors have developed a true dynamic analogy which has been used with the Cal Tech electric-analog computer for the rapid and accurate solution of both steady-state and transient beam problems. This analogy has been found well suited to the study of beams having several coupled degrees of freedom, including torsion, simple bending, and bending in a plane. Damping and effects such as rotary inertia may be handled readily. The analogy may also be used in the study of systems involving combined beams and “lumped-constant” elements.

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Static and Dynamic Performance of an Infinite Stiffness Hydrostatic Thrust Bearing

Journal of Lubrication Technology ◽

10.1115/1.3452955 ◽

1977 ◽

Vol 99 (1) ◽

pp. 106-112 ◽

Cited By ~ 7

Author(s):

N. Tully

Keyword(s):

Steady State ◽

Vibration Analysis ◽

Thrust Bearing ◽

Dynamic Performance ◽

Cone Angle ◽

Vibration Absorber ◽

Static Stiffness ◽

Load Range ◽

Normal Diaphragm ◽

Steady State Performance

A novel form of variable hydrostatic restriction is proposed which will automatically achieve a high, infinite or negative static stiffness over a substantial load range. The restrictor is formed between the bearing body and a spring mounted conical plug. The steady state performance is analyzed and design curves presented which are valid for any cone angle from zero, i.e., fixed clearance, to 90 deg which is the normal diaphragm restrictor. The dynamic response to forced sinusoidal vibrations is examined in conventional vibration analysis form and it is found that the restrictor system may be designed to act as a vibration absorber.

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Transient and Steady State Vibration Analysis of a Wavy Thrust Bearing

Journal of Tribology ◽

10.1115/1.2033900 ◽

2005 ◽

Vol 128 (1) ◽

pp. 139-145 ◽

Cited By ~ 2

Author(s):

H. Zhao ◽

F. K. Choy ◽

M. J. Braun

Keyword(s):

Steady State ◽

Vibration Analysis ◽

Thrust Bearing ◽

Numerical Procedure ◽

Operating Conditions ◽

System Stability ◽

Thrust Bearings ◽

External Perturbations ◽

Vibration Signature ◽

Transient And Steady State

This paper describes a numerical procedure for analyzing the dynamics of transient and steady state vibrations in a wavy thrust bearing. The major effects of the wavy geometry and the operating parameters on the dynamic characteristics of the bearing had been discussed in a previous paper; the present paper thus concentrates on examining the relationships between the development of the transient and steady state vibrations when operating conditions are parametrically varied. Special attention is given to the development of steady state vibrations from initial transients with comparisons and consequences to the overall system stability. Numerical based vibration signature analysis procedures are then used to identify and quantify the transient vibrations. The conclusions provide general indicators for designing wavy thrust bearings that are less susceptible to transients induced by external perturbations.

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