Mechanical Properties And Multi-objective Arrangement Optimization Method Of Prefabricated Shear Wall With Concealed Braces Connected On Beam

Steel frame-steel reinforced concrete shear wall is a typical doule lateral force resisting structure widely used in nulti-story and high-rise steel buildings.It has the advantages of high bearing capacity,high ductility,excellent seismic and fire resistance.However,the practical application of steel frame-steel reinforced concrete shear wall is restricted by the following two key problems:Firstly,the optimal structure shceme is difficult to quickly design with the traditional‘calculation–check’method;secondly,it is difficult to achieve rapid installation with lots of wet operation construction.Therefore,a beam connections’prefabricated shear wall with concealed braces is proposed based on the traditional full connection steel reinforced concrete shear wall,and it could be flexibly arranged and quickly installed.Moerover,the mechanical properties,an structure’s simplified calculation method and arrangement multi-objective optimization mode are studied in this paper.With these research results,the efficient performance-based design of steel frame-prefabricated shear wall with concealed braces connected on beam could be realized.To solve the above problems,this paper has carried out the following research work:（1）Considering the rapid assembly of the multi-story and high-rose steel structure buildings,a beam connections’prefabricated shear wall with concealed braces（BCPSW）is proposed.Nine 2/3 scale specimens of beam connections’prefabricated shear wall with concealed braces was designed and tested under low-cycle cyclic horizontal shear loading,several typical failure models were analyzed,and the shear-bearing capacity,ductility,energy dissipation capacity and stiffness degradation regularity of different specimens were studied.Then,the refined finite element hysteretic simulation models were established to analyze the force transmission menchanism of the beam connections,the shear sharing proportion of shear wall’s components.57 finite element hysteresis analysis models were established with different parameters of material strengeth,shear wall geometry,steel skeleton geometry and beam conncetion’s bolt numbers.With the result of finite element parametric analysis,different beam connections’prefabricated shear walls’change mechanism of characteristic performance and components’shear sharing proportion were analyzed.（2）A calculation method of steel frame-prefabricated shear wall with concealed braces connected on beam structure were studied with the test and finite element analysis results.The stiffness composition and degradation regularity of typical beam connections’prefabricated shear wall with concealed braces were clarified,and the calculation models of shear wall’s lateral stiffness（k_m）,cracking load(P_ck),peak bearing capacity(P_max)and restoring force characteristic curves are proposed,respectively.Furthermore,the structure’s elastic interlayer lateral stiffness calculation model were established with the column’s elastic lateral stiffness D value method.The beam connections’prefabricated shear wall with concealed braces’equivalent bar stiffness model were proposed by the shear wall’s lateral stiffness（k_m）,and the steel frame-prefabricated shear wall with concealed braces connected on beam structure’s internal force and displacement simplified calculation method was formed with matrix displacement method.（3）The relationship between the beam connections’prefabricated shear wall with concealed braces’lateral stiffness and the structure’s lateral limit and the suitable period is clarified,and the structure’s shear wall total stiffness interval calculation method were proposed by the relationship.The structure’s torsional displacement ratio and torsional period ratio were efficient calculated by the Matlab programming with the structural simplified analysis model and free vibration equation.Then,an shear wall arrangement optimization model of steel frame-prefabricated shear wall with concealed braces connected on beam structure was established.And in this model,the structure’s torsional displacement ratio,torsional period ratio,later displacement and components’bearing capacity limited as constraint indexes,the structure’s total cost of material and construction as the objective function.Thus,the selection of the component’s section,and the optimization arrangement of the prefabricated shear wall with concealed braces connected on beam structure could be realized with minimum cost principle.（4）With the proposed retoring force model of the prefabricated shear wall with concealed braces connected on beam,a structural total energy consumption objective function of steel frame-prefabricated shear wall with concealed braces connected on beam were proposed.The variation of structural total cost and total energy consumption with different beam section,column section,and shear wall length were analyzed,and the approximate cost interval division criterion were propsed.Furthermore,a coordinated objective function that could coordinate the reduction of the structure’s total cost and the increase of the structure’s total energy consumption were established.Then,the selection of the component’s section,and the optimization arrangement of the prefabricated shear wall with concealed braces connected on beam structure could be realized by this multi-objective optimization model.（5）An efficient improvement strategy for population coding,selection and crossover of genectic algorithm were proposed in this paper’s optimization model.An automatic extraction program for the shear wall arrangement’s length constraint boundary in building drawings were developed with the Matlab image digital conversion function.The multi-objective optimization program of steel frame-prefabricated shear wall with concealed braces connected on beam were complied by using Matlab.And,the automatic input of the shear wall arrangement’s constraint boundary,the automatic optimization selection of the component’s section,and the automatic optimization arrangement of the prefabricated shear wall with concealed braces connected on beam could be realized with this programs.