風による吊屋根の振動

Abstract

Since suspension roofs or curved membrane roofs are usually flexible, there exist twoimportant problems with regard to dynamic instability in wind-induced vibration of theseroofs, one is of flutter which wind with constant velocity can induce and another is of aresonance due to periodical character of wind velocity fluctuations in atmospheric turbulence, and both problems are examined here. If wind is assumed as inviscid potential flow and ifvorticities are introduced to represent the difference of velocities of wind and roofs in orderto take into consideration the wind-roof interaction effect, flutter critical wind velocity canbe determined as the wind velocity at which positive aerodynamical damping effect vanishesand the latter problem can be analyzed as that of parametric resonance in anti-symmetricdeflection modes. Analytic solution and numerical results for an example are presentedconcerning the several important factors which govern the prevention of flutter or parametricresonance.