Vibration-Reduction Of Single-Layer Reticulated Domes With Vibration Reducing Bearings

Single-layer reticulated dome is a kind of large-span spatial structure, which is developing towards complexity, diversification and spatiality with the progress of economy in our society. Single-layer reticulated dome has a relatively low damping so that it is sensitive to the earthquakes. Therefore, vibration control is significant to the single-layer reticulated dome. The technology of structural vibration control, which can restrain and reduce structural responses due to dynamic loads by setting up energy dissipating or vibration reducing devices, has been utilized in civil engineering. In this paper, vibration reducing analysis was carried out for single-layer reticulated domes in which all horizontal pin bearings were changed as spring bearings or damped spring bearings. The main research contents are stated as follows:Firstly, research on dynamic performance of single-layer reticulated domes was carried out. The differences of the natural periods and the vibration modes between uncontrolled and controlled structures were studied in order to illustrate the vibration reducing mechanism of the reticulated domes.Secondly, systematically analyze the vibration reducing effects of single-layer reticulated domes. From a large number of parameter analyses, the structural maximum horizontal displacement at bearings and maximum reactions at bearings were calculated under frequent earthquakes. With the rigidity of the vibration reducing bearings changing, vibration reducing effects were compared.Thirdly, put forward a strengthening method in vibration reducing analysis of single-layer reticulated domes. With the rigidity of the vibration reducing bearings changing, the static stability and the vibration reducing effect of reticulated domes have been compared, respectively. It is shown that the static stability decreases with an increase of the vibration reducing effect. Therefore, to overcome this contradiction,the author advanced a design method as the ring stiffener system.Fourthly, Static and vibration reducing analyses of single-layer reticulated domes with the ring stiffener were carried out. The safety degrees and the vibration reducing effects of single-layer reticulated domes with the ring stiffener were compared respectively, and systematically analyze the influence of different sections and different numbers of ring stiffeners on the safety degree of single-layer reticulated domes.Finally, preliminary suggestions on design methodologies were put forward in this paper including the rigidity and damping of bearings and the design of ring stiffener.