Study On The Prestressed Cables' Optimum Design Of The Large-span Elliptic Suspendome

With the technology of large span space structures' rapid development,the suspendome system is more and more common in our sights,especially the elliptic suspendomes.Six models under the form factors of 0.5 to 1.0 are used to analyze the common suspendomes' structure performance by Midas Gen 800.The results show that the form factor is a great influence on the structure performance.With the increase of the form factor,the trend of the load's transmission along the direction of short span weakens and the nodes' vertical displacements increase.A smaller form factor makes the ring cables' and the stay bars' internal forces' distribution more irregular.In order to improve the above results,a new type of suspendome structure is put forward.Four models under the form factors of 0.5 to 0.8 are used to analyze the new suspendomes' structure performance by Midas Gen 800 and SAP 2000.After the contrast between the common and the new structures,some results are as follows:Because of the number of the new one's stay bar is less than the common one's,so the new one has a higher level of nodes' vertical displacements.But the bigger ones mostly distribute between the two parts of the ring cables.To the structure of low form factor,the new type can reduce the level of ring cables' internal forces and makes them symmetrical.With the form factor increase,this effect goes down.However,the new type makes the stay bars' internal forces very irregular.In this paper,the two types' self vibration characteristics are analyzed.The new type has its own self vibration characteristic: the two parts of the structure vibrate independently.Analysis of time history responses to the new one under the form factor of 0.6 has done in this paper.The result shows that the vertical displacement is the major one in three directions and the time when the maximum appears is a little late on the ring cables' part.This paper shows that the new type of suspendome is tenable and it has its own structure performance.After analysis,the new type of suspendome applies to the structures under the form factors from 0.5 to 0.7.