新型张弦巨型网格结构受力性能及抗震性能研究

发布时间：2019-03-14 11:44

【摘要】：人类社会的发展,对空间结构的跨度提出了更高的要求,以满足现代大型场馆建设的需要。然而,单一形式的结构已无法满足超大跨度的需求。为此,各国科技工作者不断地进行探索,将几种单一形式的结构进行有机组合,以改善结构受力性能,增加跨度。张弦梁结构是目前应用广泛的一种大跨组合空间结构,由下部撑杆、拉索以及上部刚性压弯构件组成;巨型网格结构是近些年提出的一种新型空间结构,由承担整个结构荷载的大网格和承担局部荷载的子结构组成。为进一步提高结构跨度,改善结构受力性能,本文将张弦梁概念引入巨型网格结构,从而组合成为一种新型超大跨空间结构——张弦巨型网格结构,并从布索方案、静力及稳定性能、动力特性、抗震性能等几方面对该结构进行系统的理论研究。首先针对该新型结构提出了5种可能的索杆布置方案,研究了矢跨比对不同布索方案结构变形的影响,然后对同一矢跨比下各结构的内力、变形、稳定承载力及失稳模态等方面进行了综合对比分析,选出最佳布索方案。对优选方案下结构的变形、内力、稳定极限承载力及各自的变化率进行一系列参数分析并与同样形式的未布索结构作比较,给出各参数的最佳取值范围;然后针对结构在不同跨度、矢跨比及桁架梁高度时的最佳预应力进行了大规模计算,得到各几何参数下结构的最佳预应力取值范围;最后讨论了结构稳定性能在半跨荷载作用下的变化情况。研究了结构的动力特性,以整体结构各阶振型及相应自振周期为指标,根据子结构是否参与协同承载分两种情况进行对比分析,并对首阶各向振型的出现次序及相应周期值进行参数分析,且与未布索结构作比较,详细研究了结构各向刚度随参数的变化情况。对结构抗震性能进行了详细的研究,分别考察结构各地震响应指标在单向和多向地震作用下的变化情况。考虑单向地震作用时,首先使用时程法及反应谱法研究结构抗震性能在各向地震作用下的分布规律,然后对结构抗震性能进行参数分析;对于多向地震,使用时程法,首先研究三维地震作用对结构基本抗震性能的影响,然后对不同地震组合下结构各地震响应指标进行对比分析,选出设计时宜采用的最佳地震组合,最后对结构内力及位移地震响应进行参数分析,给出结构抗震设计时各参数的合理取值范围。
[Abstract]:With the development of human society, higher requirements for the span of spatial structure are put forward to meet the needs of modern large-scale stadiums and stadiums. However, the single-form structure can no longer meet the needs of the super-large span. In order to improve the mechanical performance of the structure and increase the span, scientists and technicians from all over the world continue to explore and organically combine several kinds of single-form structures in order to improve the mechanical performance of the structure and increase the span. Beam string structure is a kind of long-span composite space structure which is widely used at present. It is composed of lower brace cable and upper rigid bending member. Mega-grid structure is a new type of spatial structure proposed in recent years, which consists of a large grid bearing the whole structure load and a sub-structure bearing local load. In order to further improve the span of the structure and improve the mechanical performance of the structure, the concept of Zhang string beam is introduced into the mega-grid structure in this paper, so as to form a new type of super-span spatial structure-Zhang Xian mega-grid structure, and from the cable placement scheme. The static and stability performance, dynamic characteristics and seismic performance of the structure are studied systematically. Firstly, five possible cable-bar layout schemes are proposed for the new structure, and the influence of the rise-span ratio on the deformation of different cable-laying schemes is studied. Then, the internal force and deformation of each structure under the same rise-span ratio are studied. The stability bearing capacity and instability mode are compared and analyzed synthetically, and the best cable layout scheme is selected. In this paper, the deformation, internal force, ultimate stability bearing capacity and their rate of change of the structure under the optimum scheme are analyzed by a series of parameters and compared with the same type of unarranged cable structure, and the optimum range of each parameter is given. Then a large-scale calculation is carried out for the optimum prestress of the structure under different span, rise-span ratio and truss beam height, and the optimum prestressing value range of the structure under each geometric parameter is obtained. Finally, the variation of structural stability under half-span load is discussed. In this paper, the dynamic characteristics of the structure are studied, and the dynamic characteristics of the whole structure are compared and analyzed according to whether the sub-structure is involved in the co-loading or not, taking the vibration modes of the whole structure and the corresponding natural period as the indexes. The order of appearance of the first-order modes and the corresponding periodic values are analyzed, and the variation of the stiffness with the parameters is studied in detail compared with the non-cable-laying structure. The seismic performance of structures is studied in detail, and the changes of seismic response indexes of structures under unidirectional and multidirectional earthquakes are investigated respectively. In the case of unidirectional seismic action, the seismic behavior of the structure is studied by time-range method and response spectrum method, and then the seismic performance of the structure is analyzed by parameter analysis. For multi-directional earthquakes, the effects of three-dimensional seismic action on the basic seismic performance of structures are studied firstly, and then the seismic response indexes of structures under different earthquake combinations are compared and analyzed. The optimum seismic combination is selected for the design. Finally, the parameters of the internal force and displacement of the structure are analyzed, and the reasonable range of the parameters in the seismic design of the structure is given.
【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】：TU399;TU352.11

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