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Kapcsolat
Vasbeton gerenda tranziens rezgése |
Tartalom: | http://real.mtak.hu/43636/ |
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Archívum: | MTA Könyvtár |
Gyűjtemény: |
Status = Published
Type = Article |
Cím: |
Vasbeton gerenda tranziens rezgése
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Létrehozó: |
Huszár, Zsolt
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Kiadó: |
Akadémiai Kiadó
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Dátum: |
2012
info:eu-repo/date/embargoEnd/2032-09-30
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Téma: |
TH Building construction / mĂ©ly-Ă©s magasĂ©pĂtĂ©s
NA Architecture / Ă©pĂtĂ©szet
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Tartalmi leírás: |
A repedĂ©sek megjelenĂ©se jelentĹ‘s mĂ©rtĂ©kben befolyásolja a vasbeton gerendák dinamikai viselkedĂ©sĂ©t. Ha rezgĂ©s közben a repedĂ©sek kváziperiodikusan megnyĂlnak Ă©s zárĂłdnak, akkor a repedezett zĂłnában a hajlĂtĂłmerevsĂ©g idĹ‘ben változik, a rezgĂ©s nemlineáris jelleget mutat mĂ©g akkor is, ha a feszĂĽltsĂ©gek az arányossági határon belĂĽl vannak. Jelen tanulmányban azt vizsgálom, hogy ez a jelensĂ©g milyen hatással van a rezgĂ©s spektrumára, hogyan alakulnak a domináns frekvenciák.
A diszkrĂ©t Fourier-transzformáciĂł mozgĂłablakos változata segĂtsĂ©gĂ©vel megmutattam, hogy amennyiben a rezgĂ©s kezdeti szakaszában a gerenda repedĂ©sei kváziperiodikusan nyitĂłdnak Ă©s zárĂłdnak, akkor a tranziens rezgĂ©s domináns frekvenciája fokozatosan csökken. Ha a repedĂ©sek már nem zárĂłdnak, akkor ez a rezgĂ©si frekvencia elĂ©ri a berepedt gerendán csökkentett merevsĂ©ggel – lineárisan – számĂthatĂł Ă©rtĂ©ket. | The anticipated age limit of the important engineering structures covers approximately 50–75 years. During this lifetime the constructions are sometimes exposed to extraordinary effects that could cause certain damages. Damage detection method of the structures is a subject that has received considerable attention not only in civil engineering but also in the mechanical engineering, especially in the aeronautical industry. One of the most important non-destructive damage detection techniques is based on the change of the dynamic properties of the structures. The dynamic behaviour of bent reinforced concrete beams in elastic range is significantly influenced by cracks caused by former loads. In this paper basically the effect of the quasi-periodic opening and closing of cracks is analyzed. The bending rigidity of the cross-sections in the cracked range depends on the sign of the actual bending moment. The flexural stiffness of the cracked reinforced concrete beam, in bending vibration, changes quasi-periodically. Therefore the vibration shows nonlinear characteristics in the elastic range as well. The cracked zone causes a geometric non-linearity. It was shown by numerical simulation of the vibration of symmetrically cracked beams (time history analysis, Fourier transformation) that a double peak could appear in the spectrum in place of the first natural frequency if there was an appropriate relation among the starting impulse, the self-weight and the damping. Applying the moving window in the discrete Fourier analysis of the cracked beam it was also shown how the virtual natural frequency of the elastic transient vibration decreases in time, if quasi-periodic opening and closing of cracks took place in the vibration. |
Nyelv: |
magyar
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Típus: |
Article
PeerReviewed
info:eu-repo/semantics/article
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Formátum: |
text
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Azonosító: |
Huszár, Zsolt (2012) Vasbeton gerenda tranziens rezgĂ©se. ÉpĂtĂ©s - ÉpĂtĂ©szettudomány, 40 (3-4). pp. 293-311. ISSN 0013-9661
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Kapcsolat: | |
Létrehozó: |
info:eu-repo/semantics/embargoedAccess
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