Study On Section Size Optimization Of Buckling-Restrained Braced Composite Frame Columns

As early as in the 1970s,De.Jong has carried out a lot of optimization experiments on pure numerical functions using genetic algorithm.With the increasing innovation of scientific computer,the operation value of genetic algorithm is not only reflected in the optimization of pure numerical function,but also more and more attention has been paid to the optimization of building structure in recent years.At present,more and more people use genetic algorithm to establish mathematical models and optimize the design of beam and slab of frame structure,but there are few structural optimizations related to the section size of column in frame structure,because in most people’s view,frame column is one of the most important lateral resistance components of frame structure,if the section size of frame column is optimized,it will be.Make the structure more unsafe.In this paper,the Buckling-proof brace composite frame is used to make the lateral stiffness of frame structure consist of buckling-proof brace and frame column,so as to reduce the dependence of frame structure on frame column,and the frame structure can also get rid of the deficiency of integral stiffness in the past.Based on this premise,this paper uses the core optimization idea of genetic algorithm to compile the optimization program based on mode decomposition response spectrum method and D value method.The maximum interlayer displacement angle corresponding to compromise solution in multi-objective optimization is taken as the constraint condition,the section size of concrete filled steel tubular column is taken as the design variable,and the corresponding objective function is added to establish the relevant mathematical model,and finally the concurrent results are obtained.Considering the optimum results of frame column optimization,such as seismic performance,economy,building structure function,etc.The specific research work completed in this paper is as follows:1.Preliminary introduction of composite frame structure,the origin and developmentprocess of genetic algorithm are summarized,and the research purpose,significance and ideas of optimization design method of composite frame column based on genetic algorithm mechanism are expounded.2.The detailed realization methods of optimization program are described,including the software needed for programming,the operation mechanism of genetic algorithm and the design of specific parameters,the calculation method of lateral stiffness of the integral structure of buckling-resistant braced composite frame based on D-value theory and the mathematical model related to optimization,and the optimal design scheme for buckling-resistant braced composite frame structure is further clarified.3.Establish four kinds of common residential models of frame structures with different stories and adopt multi-objective optimization method to determine the optimal lateral stiffness ratio of frame structures under frequent earthquakes.According to the corresponding conversion formula,determine the layout amount of anti-buckling braces in the structure,and then arrange the structure position of anti-buckling braces for the corresponding frame structure model.Secondly,the optimization program has been designed to optimize the elastic stage of the composite frame structure model with buckling-resistant braces based on the principle of mode decomposition response spectrum method,and the optimization scheme of the section size of the frame column has been obtained.Finally,the static non-linear analysis and dynamic time-history analysis of the optimized model and the pre-optimized model under rare earthquake conditions are carried out.The analysis results show that the optimized model can weaken the seismic effect of the structure to a certain extent and improve the economic index of the project.4.Establish a concrete design method oriented by practical engineering application,and use this design method to optimize the cross-section of frame column in practical engineering.The optimized composite frame can save 1821.08 tons of concrete material and 6.28 tons of steel consumption compared with the original design of frame structure column,which has a certain engineering economy;moreover,the optimized composite frame can save 1821.08 tons of concrete and 6.28 tons of steel consumption.The proportion of energy consumption of architecture components is reasonable.