جستجوی مقالات مرتبط با کلیدواژه ": bulbous dome" در نشریات گروه "تاریخ"

Bulbous domes are among discontinuous double-shell domes and were built in Iran in the early nineth century A.H. Previous domes were shaped pointed and there was no bulge coming out beyond their base diameters. But in the Timurid period, dome profile was changed so that it began a return below the base of the arch, producing thereby a slight bulge. The main question is that what are the reasons for the changes in the appearance and structural elements between two shells after the initial formation of these domes in Central Asia and then their evolution in Iran. This research is written with the aim of finding the hidden aspects in the development of bulbous domes based on both historical documents, and architectural remains, and also examines the reasons of the changes created in these kinds of domes during four centuries in the context of cultural Iran. This study has a descriptive-analytical approach for exploring case studies, which are selected based on primary and secondary sources and also field research. The appearance changes of bulbous domes include removing flutes from the outer shell, adjusting the height of the drum and creating more bulge at the place where the outer shell joins the drum. In this article, the structural changes to improve the strength of the domes, the change in the number and proportions of the stiffeners to prevent the damage of the dome, as well as the shape and arrangement of the wooden struts to increase domes flexibility against seismic shocks, have been examined.

Bulbous domes are among discontinuous double-shell domes and has been developed in Iran since the middle of the 9th century AH/ the 15th century AD, concurrent with Timurid period. In this shape of domes, the dome profile was changed so that it began a return below the base of the arch, producing thereby a slight bulge that. The terminology for bulge in Iranian architecture is Avgun. Bulbous dome is considered as a part of Iranian architectural culture and the architects of this land have used this complex structure in a way that has been developing ever since its formation. It seems that this shape of dome requires a precise assessment in terms of design, mechanism of power transmission, and features of structural elements. The main purpose of this paper is to show the role of Avgun as an architectural structure in the bulbous domes, which supposed to have just an aesthetic function. In this study, the bulbous dome of Shah Mosque was simulated using Abaqus software. Then, its responses to the static and dynamic loads were tested. In order to show the Avgun role, this dome was compared with another dome, without Avgun, that possessed all similar architectural characteristics. The analysis revealed that Avgun is not just an aesthetic feature and that its prevalence had a structural reason too; So that Avgun reduces the amount of the dome's weight pressure on the dome chamber bases.