Dynamic Collapse Analysis of Reticulated Shell Structures with Substructures

Abstract

xqren@126.com Abstract—Dynamic collapse analysis is an important research subject for large span single layer reticulated shell structures. In this paper, the dynamic collapse behavior of the single layer reticulated shell with substructure which supports the reticulated shell is investigated under the earthquake actions. In the analysis, the geometric imperfections, the material and the geometric nonlinear of the structures are considered. The effects of the different stiffness of substructure to the collapse earthquake accelerations and the plastic member distribution of the reticulated shell are investigated. Reticulated shell structure is a basic type of the large spatial structures. And it is widely used in engineering due to its attractive architectural performance and the good load bearing capacity. Because the membrane force is the main resistance force of the reticulated shell structures under loads, the stability behavior of this type structure is a controlling factor in the analysis and design. The stability behavior includes static stability and dynamic stability. In the past decades, the static stability of the reticulated shell structures has been extensively studied, and a lot of research results have been got (1-4). In recent years, the dynamic collapse of the reticulated shell caused by the earthquake action also attracts a lot of researchers, and a series of the investigation results have been presented (5-8). But up to now, most of the dynamic collapse analysis papers considered only the reticulated shell itself and neglected the supporting frame structures, namely substructures. In practical, most spatial structures have a supporting frame or called, substructure. During an earthquake, the effects of seismic ground motions act on the base of these substructures and then these effects are transmitted up into the main reticulated shell structure. In this respect, an accurate and realistic investigation of the behavior of earthquake resistant spatial structures would be achieved if the reticulated shell structure and the supporting frame (substructure) are considered as an integral whole. To date, there are only a few papers published concerning this issue (9-11). This paper considers the reticulated spherical shell structure and the substructures as an integral whole and investigates the dynamic collapse behavior of the reticulated shell under earthquake actions. In the analysis, the initial geometric imperfections together with geometric and material nonlinearities are all included, and the reticulated spherical shells with substructures of the different stiffness are analyzed to demonstrate the effects of stiffness on the dynamic collapse of the structures.