ISSN:
1570-1468
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Conclusions 1. The frequency of free vibrations of ribbed gates in the air and the magnitude of the affected water mass when the gate is immersed in water are amenable to quite simple and sufficiently accurate calculations. For gates similar to those discussed it is permissible to determine ν0 as for a beam supported at the ends with shear deformation taken into account. It is recommended that the affected water mass be computed by Eq. (1) and a coefficient K=0.4. 2. Gates with clearly expressed ribbing (i. e., such in which almost the entire mass and rigidity are concentrated in several planes-planes of widely separated ribs connected with transverse ties of slanting type) are characterized by independent dynamic operation of the ribs as independent vibrating systems. The hypothesis of geometrically unchanging transverse ties is confirmed in static calculation: its application in dynamic computation when the determining role is played by inertial forces does not reflect the physics of the actual process. Having determined the natural frequencies of each of the ribs one can consider the average value as the natural frequency of the gate. 3. As a result of the investigation it was found that owing to the presence of a reverse relation between the pulsation of pressure and pulsation of the bar the system of the gate in water exhibits a tendency toward hydroelastic autovibration processes of natural frequency. Therefore, the determination of inherent vibration characteristics of the gate becomes of special importance in its design. Because of its complexity, the mechanism of arising of autovibration is as yet not fully clear and investigations in this direction must continue.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02376281
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