Time-history Analysis Of Special Truss Moment Frames With Vierendeel Web Members

Frame structure is a common structure system in high-rise steel structure, when the span is larger, it is not economic if we still adopting solid-web steel beam. Steel truss has better flexural capacity than the solid-web steel beam, especially suitable for large span structure. If we use Steel truss to replace the solid-web steel beam, it formed a kind of new structure, called the truss frame structure in this paper. The carrying capacity of this structure can achieve the large span building requirements, but the seismic performance is poor. To set energy dissipati-on segment near the mid-span of trusses in the vierendeel truss moment frames, the seismic performance can be significantly improved. This new type of structural system has a very good application prospect, but less relevant research data at home and abroad, it is necessary to study their seismic performance.In this paper, four series of truss frame structure are analyzed under the action of frequent earthquake and rare earthquake by using the finite element software ANSYS, mainly discussed the energy dissipation length, the stories of the structure, the number of spans and the type of seismic wave impact on structures. The analysis results show that:the energy dissipation length has a great influence on the truss frame structure of the failure mode and energy dissipation of reasonable length can achieve shear yield, and significantly reduce the structural base shear. Compared to the common frame structure, the truss frame structure has the longer the basic cycle, and gradually increases with the increase in length of the energy dissipation. The layers of the structure and the type of seismic waves have little effect on the failure mode of the truss frame structure. With the increasing number of layers, the structure of basic period is increased gradually, and the vertices of the horizontal displacement is also gradually increases. Different span truss frame structure has the same failure mode, and the basic cycle is relatively close, but the shear force increases with the span number. Because the single span truss frame structure is low safety, should be avoided as far as possible in the actual application. By adjusting the length of energy dissipation segment, we can make more floors synchronization occurs to yield. Therefore, the structure of the energy dissipation capacity is improved. In addition, with the energy dissipation segment in the truss frame structure, the structure fundamental period lengthen, and the lateral stiffness is reduced. Therefore, it may could not meet the specifications of the story drift limit requirements.Based on the finite element analysis results, the characteristics of special truss moment frames with vierendeel web members are summarized, and provide a reference for future theoretical research and practical application. Finally, I put forward relevant suggestions on the deficiencies and future research.