The Elastic-plastic Stress Analysis Of Steel Structure With V-braced Steel Frames

The braced steel frame structures with lateral stiffness, good ductility, light weight,flexible structure, good anti-seismic performance, has become a trend of the development ofhigh-rise buildings in recent years. This paper uses static pushover and dynamic elastic-plasticmethod to analyze of steel Structure with v-braced steel frames behavior of the seismicperformance.This paper established a six layer, a nine layer, a twelve layer of the three cross bracedsteel frame structure model. In Pushover analysis, plastic hinge were used in beam, columnends and braced middle in order to model nonlinear deformation in SAP2000, and two loadPatterns were adopted with displacement control. Under the two lateral loading, the paperuses capacity spectrum method to get load-displacement curves, the plastic hinge generatedsequence and the weakest position of the structure. Then the paper summarizes the influenceof the pushover curve and the plastic hinge location of the hinge sequence under the differentlateral load patterns. Analysis results show that: the structure of the weak layer in the structureof fourth layers; under the eight degrees frequently occurred earthquake, brace supporting afew plastic hinges, the frame is in elastic stage; under the eight rarely occurred earthquake,brace supporting the emergence of a large number of plastic hinge and into the ultimatebearing capacity, beams supporting small plastic hinge and into the immediate use of phase,column in the elastic phase; v-braced steel frames structure has good seismic performance byforce, meet the requirements of seismic design code for "no damage in small earthquake,repairable under moderate earthquake, earthquake does not fall" three fortification level.The steel frame was modeled with bar systems, the restoring force model with Cloughstiffness degradation model, three kinds of the Earthquake waves were adopted in the thesis, i.e. EL一CENTRO wave, LanZhou3wave and taft₃0s wave. The results show that: the weak layer of6layer structure in the structure of fourth layers, the weak layer of9layer and the12layer structure in the structure of seventh layers; Artificial seismic wave analysis resultssignificantly smaller, two natural seismic wave analysis results are very close to.The two methods both can accurately evaluate the weakness and the destructive situationUnder high earthquake, so they were considered as effective method for thePerformance-based design. Then, according to the comparative result, it can be seem that twomethods are almost consistent. two analysis methods are in good faith for rules and morehigh-level frame structure.