The Elasto-Plastic Analysis Of The Steel Frame Structure On The Seismic Action

Currently the nonlinear analysis method is a hot spot in the steel structure fundamental research. Nonlinear analysis ,namely, is to consider all important nonlinearity factors sufficiently in structural analysis, thus may carry on comprehensive evaluation to the structure's actual failure mode, and obtains the overall limit supporting capacity of the structure directly, thus uses in the advanced design. The main nonlinear analysis method includes nonlinear static method and nonlinear dynamic analysis. Nonlinear static method is also called Pushover method, which mainly considerats lateral load pattern, and judges the structural unit to submit from the condition. Under rarely earthquake function, the structure will enter the elastoplasticity stage, the structure's rigidity changes, and also presents the plastic stress redistribution . If the structure has big torsional effect, but has not obtained in the pushover analysis manifests, by now the elastoplasticity result confidence level greatly to reduce rarely,which provided by static Pushover analysis under the srong earthquake . If we consider the material misalignment (plastic hinge) of the frame unit in the time history analysis, then the non-line time history analysis may give the member's yield order under the srong earthquake, discovered that the stress and the plastic deformation centralized spot, gives the yield mechanism of the entire structure, provides the corresponding adjustment opinion to the structure conceptual design.This paper has established the steel frame computation model, useing two analysis methods: nonlinear static method and nonlinear dynamic analysis. Meanwhile,it has carried on the overall nonlinear analysis of the spatial steel frame construction by the finite element software SAP2000 (main consideration geometry, material dual misalignments). Two methods have both educed the possible weakness lever and the weakness menmber which would appear in the structrure on the seismic action. Through the contrast to two kind of analysis results, the law of plastic hinge's distribution and development among the side pin and cetral pin would be found in the tapping portal frame construction, simultaneously the attentive problems during the practical design were proposed in this paper.