Untitled in english

Author(s)

André Luís Condino Fujarra

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Escola Politécnica (EP/BC)
• Defense date: 1997-12-18

Examining board members

Celso Pupo Pesce; Jose Augusto Penteado Aranha; Segen Farid Estefen

• Advisor: Celso Pupo Pesce

Abstract

Experiments have been conducted with a reduced model, flexible and smooth, in order to investigate the vortex induced vibration phenomenon V.I.V..Fourteen sections of a vertically suspended submerged tube (cantilever beam) were instrumented by pairs of strain gages and in some cases na accelerometer was used at lower extremity of the model. Time histories of deformation were taken in a range of Reynolds number from approximately 6x103 to 4x104. In this range, the frist mode was excited and the obtained signals, under some treatment, showed results so consistents and with an hysteresis panorama at superior part of lock-in range, as well as discussed by Parra & Aranha (1996), for example. The mainly aim of this study was to compare experimental results with those coming from a lock-in based method, supported by V.I.V. Iwan & Blevins Model, trying to identify its real consistency. Another aim was to analyze the correlation between measurements along the experimented model. (AU)