Experimental modal analysis on the core support barrel of reactor internals using a scale model

1999 ◽  
Vol 13 (8) ◽  
pp. 585-594 ◽  
Author(s):  
Seon Ho Song ◽  
Myung Jo Jhung
2015 ◽  
Vol 39 (1) ◽  
pp. 145-149 ◽  
Author(s):  
Ewa B. Skrodzka ◽  
Bogumił B.J. Linde ◽  
Antoni Krupa

Abstract Experimental modal analysis of a violin with three different tensions of a bass bar has been performed. The bass bar tension is the only intentionally introduced modification of the instrument. The aim of the study was to find differences and similarities between top plate modal parameters determined by a bass bar perfectly fitting the shape of the top plate, the bass bar with a tension usually applied by luthiers (normal), and the tension higher than the normal value. In the modal analysis four signature modes are taken into account. Bass bar tension does not change the sequence of mode shapes. Changes in modal damping are insignificant. An increase in bass bar tension causes an increase in modal frequencies A0 and B(1+) and does not change the frequencies of modes CBR and B(1-).


Author(s):  
B. Z. Margolin ◽  
A. Ya. Varovin ◽  
A. J. Minkin ◽  
D. A. Gurin ◽  
V. A. Glukhov

The program is presented for investigations of the metal of the most irradiated elements of the WWER-440 reactor of the Novovoronezh NPP Unit 3 decommissioned after 45 years of operation. The fragments (cylindrical samples) were cut out from various zones of the core baffle and segment of forming ring of core barrel.


2013 ◽  
Vol 486 ◽  
pp. 36-41 ◽  
Author(s):  
Róbert Huňady ◽  
František Trebuňa ◽  
Martin Hagara ◽  
Martin Schrötter

Experimental modal analysis is a relatively young part of dynamics, which deals with the vibration modes identification of machines or their parts. Its development has started since the beginning of the eighties, when the computers hardware equipment has improved and the fast Fourier transform (FFT) could be used for the results determination. Nowadays it provides an uncountable set of vibration analysis possibilities starting with conventional contact transducers of acceleration and ending with modern noncontact optical methods. In this contribution we mention the use of high-speed digital image correlation by experimental determination of mode shapes and modal frequencies. The aim of our work is to create a program application called Modan 3D enabling the performing of experimental modal analysis and operational modal analysis. In this paper the experimental modal analysis of a thin steel sample performed with Q-450 Dantec Dynamics is described. In Modan 3D the experiment data were processed and the vibration modes were determined. The reached results were verified by PULSE modulus specialized for mechanical vibration analysis.


Author(s):  
Barış Erdil ◽  
Mücip Tapan ◽  
İsmail Akkaya ◽  
Fuat Korkut

The October 23, 2011 (Mw = 7.2) and November 9, 2011 (Mw = 5.6) earthquakes increased the damage in the minaret of Van Ulu Mosque, an important historical masonry structure built with solid bricks in Eastern Turkey, resulting in significant shear cracks. It was found that since the door and window openings are not symmetrically placed, they result in unsymmetrical stiffness distribution. The contribution of staircase and the core on stiffness is ignorable but its effect on the mass is significant. The pulpit with chamfered corner results in unsymmetrical transverse displacements. Brace wall improves the stiffness however contributes to the unsymmetrical behaviour considerably. The reason for the diagonal cracks can be attributed to the unsymmetrical brace wall and the chamfered pulpit but the effect of brace wall is more pronounced. After introducing the cracks, a new model was created and calibrated according to the results of Operational Modal Analysis. Diagonal cracks were found to be likely to develop under earthquake loading. Drifts are observed to increase significantly upon the introduction of the cracks.


Author(s):  
Bekir AKTAŞ ◽  
Ferhat ÇEÇEN ◽  
Hakan ÖZTÜRK ◽  
Burhan M. NAVDAR ◽  
İrfan Ş. ÖZTÜRK

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