基于IDA的倒鱼腹式空间管桁架结构地震易损性分析

发布时间：2018-04-04 11:05

本文选题：增量动力分析　切入点：大跨度　出处：《湖南大学》2015年硕士论文

【摘要】：近些年,由于经济和文化的飞速发展,人们对建筑物造型、跨度及规模的追求越来越高,而其中大跨度空间管桁架结构以其独特的优势被广泛应用于机场航站楼、展览馆、体育场馆等安全系数较高的各类公共建筑物。增量动力分析法(Incremental Dynamic Analysis,IDA)是基于性能地震工程中近年发展起来的一种能评价结构在不同地震动水准作用下性能反应的最有潜力的方法。然而,IDA方法在评估大跨度空间管桁架结构抗震性能的研究尚处于起步阶段,基于IDA方法的大跨度空间结构地震易损性分析更是鲜见报道。在这样的背景下,本文首先总结了基于性能的空间结构抗震研究历史发展现状及其存在的问题,然后介绍了基于IDA方法的结构地震易损性分析基本原理。之后,本文以某实际大跨度倒鱼腹式空间管桁架结构为研究对象,选取10条地震波,利用桁架最大节点位移、屈服杆件比例及其塑性发展程度、关键节点位移时程曲线三个结构响应指标,研究了该结构在强震作用下的失效机理。最后,对该结构进行IDA分析和地震易损性分析,并从概率论角度评价结构的抗震性能。研究结果表明,在各条地震波作用下,三个结构响应指标的分布规律基本保持一致,该结构出现在各临界状态时所对应的地震荷载幅值有所变化,结构在强震作用下倒塌时,塑性杆件数量、桁架最大节点位移也有较大不同;桁架最大节点位移、屈服杆件比例及其塑性发展程度、关键节点位移时程曲线能较好地表征大跨度空间结构在地震作用下的响应特性;由结构地震易损性矩阵可知,该桁架结构在8度三水准地震作用下达到三种极限状态(IO、CP、GI)的概率较小,在8度罕遇地震作用下倒塌概率仅为0.93%;在各条地震波作用下,地震荷载幅值各自达到某一较大值时,桁架最大节点位移、屈服杆件比例及其塑性发展程度均发生急剧变化,结构刚度严重弱化;结构承载能力较高,但延性较低;在IDA分析中,结构挠跨比是一个有效的结构性能参数来表征大跨度空间结构的抗震性能;IDA方法和地震易损性分析相结合可以有效地评估大跨度空间管桁架结构的抗震能力。
[Abstract]:In recent years, due to the rapid development of economy and culture, the pursuit of building shape, span and scale is getting higher and higher. Among them, large span space pipe truss structure is widely used in airport terminal, exhibition hall with its unique advantages.Stadiums and stadiums and other public buildings with high safety factors.Incremental Dynamic Analysis (IDA) is one of the most promising methods for evaluating the performance response of structures under different ground motion levels, which has been developed in recent years in the field of performance-based seismic engineering.However, the study of seismic behavior of long-span space truss structures using Ida method is still in its infancy, and the seismic vulnerability analysis of long-span space structures based on IDA method is rarely reported.In this context, this paper first summarizes the historical development and existing problems of performance-based seismic research of spatial structures, and then introduces the basic principles of seismic vulnerability analysis based on IDA method.Then, taking a large span inverted fish-bellied space tube truss structure as the research object, 10 seismic waves are selected, and the maximum joint displacement of the truss is used, the yield member ratio and the plastic development degree of the truss are used.The failure mechanism of the structure under strong earthquake is studied by three structural response indexes of the key node displacement time history curve.Finally, the IDA analysis and seismic vulnerability analysis of the structure are carried out, and the seismic performance of the structure is evaluated from the point of view of probability theory.The results show that under the action of various seismic waves, the distribution of the three structural response indexes is basically the same, and the amplitude of the corresponding earthquake load varies when the structure appears in each critical state, and when the structure collapses under the action of strong earthquake,The number of plastic members and the maximum joint displacement of truss are also quite different, the maximum displacement of truss joints, the ratio of yield members and the degree of plastic development of truss are also different.The displacement time history curve of key nodes can well characterize the response characteristics of large span spatial structures under earthquake.The probability of the truss structure reaching the three limit states under the action of 8 degrees and 3 leveling earthquakes is relatively small, and the probability of collapse is only 0.93 under the action of 8 degrees rare earthquakes, and when the seismic load amplitude reaches a larger value respectively under the action of each seismic wave,The maximum joint displacement, yield member ratio and plastic development degree of the truss are all changed sharply, the stiffness of the structure is weakened seriously, the bearing capacity of the structure is higher, but the ductility is lower. In the IDA analysis,The flexural span ratio is an effective structural performance parameter to characterize the seismic performance of long-span spatial structures. Combined with seismic vulnerability analysis, the seismic capacity of long-span space truss structures can be effectively evaluated.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU392.3

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