The Research Of The Connection Stiffness And The Influence On Staggered Steel Truss Structure’s Performance

Staggered steel truss structure is a new type of residential structure system whichis economical and practical. Research and development of staggered truss systemconform to our country’s residential construction development direction.In the calculation of staggered steel truss structure, we always assume that trusschord is hinged on pillars while longitudinal beam and pillars is rigid. But each kindof connection mode in engineering has certain rotational stiffness. Based on the jointstiffness, this paper studies the influence of the connection stiffness to theperformance of the steel staggered truss structure.The thesis first makes structure design of staggered steel truss structureaccording to the architectural scheme of a11-story residence in Nan Jing withSAP2000. And then analyses its mechanical behavior under the basic load conditionsand accidental combination. After scheme comparison and analysis, determine thefinal section size of components of the staggered truss structures.In order to truly simulate stress characteristics of truss chord and column weakaxis connection node, the author designs two full size models for experimentalresearch according to the chord and the column section size. The connection useover-hang end plate bolt connection type which is commonly used in staggered truss.Experiment analyzes the stress of nodes in the entire loading phase developmentsituation, got the nodes of the initial stiffness and ultimate bearing capacity, therelationship between the bending angle and the damage form of node, andcomparison of two specimens. The results show that the initial rotating stiffness ofthe joints and ultimate bearing capacity increase with the thickness of the end plate.Then using finite element software ANSYS to establish model, considering onthe real stiffness of chord and column, beam and column joints at the same time.Then calculating the deformation under static load and comparing analysis on resultsfrom the previous design. The content of the comparison include mid-span deflection,interlayer displacement, bending stress ratio, etc.Finally, the paper establishes8finite element model, and respectively comparesthe overall performance in truss structure with different node stiffness, includingmid-span deflection, interlayer displacement under the wind load, bending momentof chord and column, etc. At the same time analyzes the influence in structuraldynamic properties and the seismic performance with different node rigidity, including natural vibration period, interlayer displacement under seismic load,interlayer column shear, etc..