Dynamic Interaction Of Single-layer Reticulated Shell Structure And Supporting Structure

In the recent years, reticulated spherical shells with column supports were widely used in civil engineering, such as gymnasiums and natatoriums. During the process of designing, the supporting structures were always simplified as hinge supports without considering the influence of their stiffness. This will make the results unsafe. Nowadays, Cao Zi, et al. have simplified the supporting structures as elastic supports and promoted a simply calculation method to consider this influence. Some work has been done to consider the interaction of the shell structure and supports structure, but there are still many problems to resolve. So the dynamic behavior of Kiewitt-8-type modes single-layer reticulated shells with columns supports was analyzed in this paper as follows:The model of Kiewitt-8-type modes single-layer reticulated shells with column supports was set up and its dynamic behavior under three-dimension earthquake ground motions was analyzed. Parameters such as span and rise-span ratio, loads, section size, peak ground acceleration et al were changed to further study the dynamic behavior. It was showed it was unsafe to simplify the support structure as hinges, such as the maximum difference displacement is 600% and the maximum difference axial force is 50%.Failure mechanisms of the structure under earthquake were studied to disclose its dynamic behavior and failure modes. Two models with large stiffness difference in support columns were compared, and the results revealed it was the failure of the supports that caused the collapse of the whole structure, which was different with the failure mechanism by simplifying the supports structures as hinges.Shock absorptions supports were added to the columns supports. The stiffness and damping ratio of the shock absorptions were changed to select a group of such parameters, which had better shock absorptions effect. The dynamic behavior and failure modes of the structure with these parameters were analyzed. Two methods adding shock absorptions to the support columns were also provided and their effects on shock absorptions were also compared. The study showed that the shock absorptions could not play their role whether the stiffness was too large or too small and the shock absorptions effect was more obvious for them arranged in span interval than continuously when the stiffness was the same.