Double Nonlinear Spline Finite Element Analysis Of Cyclic Loading, Thin-walled Steel Members In The Performance Of Applications

It is well known that the steel structures behave well in case of the earthquakeresistance, so they are used more and more widespreadly in industrial and civilbuildings. The knowledge of the collapse mechanism of steel structures underseismic load is not well known The limit of width-thickness of steel plates forplastic design is still used in aseismic design It is obvious that it can not satisfy thedemand of aseismic design So it is not only necessary, but also significant fromtheoretical and practical aspect to study the response and collapse mechanism of steelstructures under seismic load.This paper introduces a method of dual nonlinear spline finite element methodon the basis of previous research on the steel structure earthquake resistance, deducesits shape function and element stiffness matrices etc., draws the mixed hardening ruleinto the method; and develops and debugs the program The result shows that,bycalculating and analyzing the problem about large deflection, elastic-plastic bucklingand post-buckling, this method has high accuracy, sound convergence and quickspeed in computing.Finally,this paper performs a parametric calculation on the behaviors of H-section columns subjected to constant axial force and cyclic bending moment. Theresult shows that the width-to-thickness ratio of flange, the depth-to-thickness ratio ofweb and the axial force all exert considerable influence on the hysteresischaracteristic of steel structures. It proves that the the method introduced in this papercan model validly distribution of plastic area. and is reasonable and valid byanalyzing buckling pattern and comparising with the result of experiment.