Finite Element Analysis Of Seismic Behavior Of The Semi Seam Coupling Beam

The coupling beam is an important component of energy reduction in the shearwalls structure, and the first line of defense in seismic fortification. The stiffness,ductility, carrying capacity and energy dissipation capacity of the coupling beam havea massive impact on the aseismic behavior of the shear walls structure. The researcherspay close attention to the investigation on the ductility and energy reductionimprovement of the coupling beam. In the high-rise building, limited to the functionalrequirements of the building and structural arrangement, coupling beams are usually inthe form of a small span-depth ratio. Studies have shown that when span-depth ratio isless than2.0, coupling beam mostly occurs brittle shear failure. Thus, the couplingbeam is unable to meet the seismic performance of the shear walls requirements.In order to improve the ductility and energy reduction of the coupling beam. Thispaper presents a novel coupling beam, name by semi seam coupling beam, forimproving the ductility and energy reduction. The semi seam coupling beam is thewhole section beam of small span-depth ratio divided into the upper and lower beamsby way of reduction of its cross-section along the longitudinal axis of the beam. Innormal service state, the semi seam coupling beam guarantees its stiffness and carryingcapacity as the same as whole section beam. Under high intensity seismic action, themiddle part concrete of semi seam coupling beam is the first place to be destroyed.Then the upper and lower beams become independent members, which is twice thespan-depth ratio of original member. By reducing the structural stiffness to increase thestructural deformation, it can ensure coupling beams simultaneously with greatercarrying capacity and well ductility. It can change the failure mode of the couplingbeam from shearing failure mode to bending or flexure-shear failure mode. So, semiseam coupling beam can absorb more seismic energy and achieve the purpose ofprotecting the shear walls structure.To verify the seismic performance of the semi seam coupling beam, the researchcontent of this paper consists of three parts.Firstly, this paper introduces the theoretical basis of ABAQUS in the concrete damaged plasticity model and the meaning of each parameter in detail. According tothe selection of concrete stress-strain relationship, calculating true stress and true strain,inelastic strain, cracking strain and damage parameter of C40concrete. Comparingnumerical example and experiment results, the selected model parameters are reliable.Secondly, Then finite element model of coupling beams are established to analyzetheir mechanical properties. Compare the mechanical properties of ordinary couplingbeam, semi seam coupling beam and dual coupling beam with span depth ratio of0.75,1.0and1.25under monotonic load and cyclic load, through modeling all three types ofcoupling beams and carrying on finite element analysis. The results show that the semiseam coupling beam showed the superiority in seismic performance, for meetingrequirements of both rigidity and ductility.Finally, analysis of the factors affecting the seismic performance of semi seamcoupling beams, such as seam height, cross diagonal reinforcement setting, span-depthratio, concrete strength grade, so as to understand the mechanical properties of semiseam coupling beams.