Experimentální vyšetřování kmitání vybraných konstrukcí, tvorba jejich modelů a analýza samobuzených vibrací štíhlých prutů se dvěma stupni volnosti

Abstract

In structural design, the dynamic wind loading is in many cases simplified to the level, where a quasi-static load can substitute it, which is reality a static loading multiplied by a coefficient expressing an integral influence of the dynamic effects. For tall and long constructions, which are also slender, this approach cannot be used. Rather, it is necessary to carry out an analysis of the structure from the point of view of both static and time and frequency dependent dynamic component of the load. This diploma work describes the experimental analysis of a bridge from the point of view of static and particularly dynamic loading, which arises as a consequence of wind-structure interaction phenomena. Here, an analysis of the self-excited oscillation of the bridge deck with a non-aerodynamic cross-section. The load is expressed with the use of so-called aeroelastic derivatives obtained by an extensive experimental campaign in the wind tunnel. The geometry of the bridge as well as the other parameters lead to the coupled oscillation in the regime of flutter that is different from the oscillations known from the auronatics. Self-excited vibration of the bridge girder, which can be described by two differential equations for two degrees-of-freedom is solved within Matlab using author’s or modified procedures.