Seismic Vulnerability Analysis Of Ship-type Tensioned String Beam Structure Based On OpenSEES

As a a kind of long-span prestressed space structure,string beam structure(BSS)has a wide application prospect.With the extensive application of BSS in the engineering,researchers have carried out lots of research and analysis on this kind of building structure,but the seismic vulnerability analysis based on the ship-formed BSS(SF BSS)is far from enough.There is also no uniform standard and method for the threshold value of each failure state of SF BSS.Therefore,the vulnerability analysis of SF BSS was carried out in this paper.By studying the collapse probability of SF BSS under different earthquake ground motion strength,the anti-collapse ability of the structure was analyzed to provide the basis for the design and construction of this kind of structures.The main contents and conclusions are as follows:Firstly,a basic model of SF BSS with span(L)of 56m and column distance(l_c)of 9m was established by using OpenSEES software to carry out the numerical simulation of the model.The influence of parameters such as prestressed,column-span ratio(l_c/L),vertical span ratio on the mechanical behavior of SF BSS were compared and analyzed to determine the reasonable values of SF BSS modeling parameters.Based on the basic model,three analysis models were established respectively with different l_c/L(analysis model 1:l_c/L=0.16,analysis model 2:l_c/L=0.21,analysis model 3:l_c/L=0.27).Secondly,the incremental dynamic analysis(IDA)under multiple seismic records on three analysis models given in chapter 2 were carried out.This paper gives the method of determining the failure limit values of SF BSS.According to the results of IDA analysis,the change trend of three analysis models entering each failure state under multiple seismic records were obtained.Furthermore,the influence of l_c/L on the structural response of SF BSS under seismic ground motion were obtained.When l_c/L is between 0.16 and 0.27,there would be more seismic records in the structural response beyond the response limit state with l_c/L increasing.Then,the seismic vulnerability analysis of three analysis models were carried out to disscuss the influence of l_c/L on the seismic vulnerability of SF BSS.Based on the deduced structural reflection probability function,the formula of structural failure probability corresponding of three analysis models were obtained,and the corresponding vulnerability curve diagram were drawn.The conclusion was achieved as follows:when l_c/L is between0.16 and 0.27,the bigger l_c/L,the higher the probability of structure entering each limit state,the worse the seismic performance is.Finally,the anti-collapse probability curves of three analysis models were drawn to discuss the influence of l_c/L on the collapse-resistance performance of SF BSS.The collapse probability of SF BSS’s three analysis models under rare earthquake are 0.22%、0.37%、1.18%,which indicates that SF BSS has good anticollapse ability.When l_c/L is between 0.16 and 0.27,the collapse resistance of SF BSS decreases linearly with l_c/L increasing.