ABAQUS-based Research On Seismic Performance Of Reinforced Masonry Infill Wall With Flexible Connections

Masonry infill wall-frame structure is one of the main structural forms of modern architecture,which has the advantages of simple construction method and flexible spatial arrangement,and has been widely used.However,the practical engineering application and a large number of seismic damage data show that there are many problems in the masonry infill wall-frame structure.First,the traditional masonry infill wall made of clay brick has large stiffness,self-weight,poor shear and tensile strength,and is prone to damage in the earthquake.Secondly,rigid connections are often adopted between the masonry infill wall and the frame,which leads to complex interactions between the masonry infill wall and the frame.The masonry infill wall will exert unpredictable influences on the internal force distribution of the frame,making the structure prone to serious damage.Therefore,it is an urgent problem to improve the seismic performance of the masonry infill wall and to find a reasonable connection between the wall and the frame to meet the seismic performance requirements.With the implementation of wall material innovation in China,autoclaved aerated concrete blocks have been recognized by the market and the government due to their advantages of light weight,high strength and green environmental protection,which can meet the requirements of strength and energy conservation at the same time.The use of basalt fiber grid to replace the lacing bars in the horizontal ash joints of autoclaved aerated concrete blocks not only meets the energy saving requirements of thin ash joints,but also improves the strength of masonry.In view of the above problems,this paper adopts finite element software ABAQUS to study the seismic performance of reinforced autoclaved aerated concrete block masonry infill connected by flexible connections.This paper mainly focuses on the following work:(1)Finite element software modeling.Based on the ABAQUS finite element analysis platform,the finite element model of the reinforced masonry infill wall-frame structure with flexible connections was established by separate and integral methods,and the simulation method of the connections between wall and frames were proposed by the linear spring elements based on damping.(2)Model validation.Based on the perspective of failure characteristics,failure mode,bearing capacity,ductility and stiffness of the model,the degree of agreement between simulation results and test results is compared to verify the applicability of the model proposed in this paper.(3)Analysis of seismic performance factors outside the plane of reinforced wall-frame structure with flexible connections.Based on the finite element model proposed in this paper,the effects of the constraint conditions of the masonry infill frame,vertical load,block strength level and other factors on the seismic performance in the plane of the filled wall are studied from the perspectives of the plastic development,damage accumulation,bearing capacity,ductility and stiffness degradation of the wall.(4)Analysis of the seismic performance outside the packed wall plane.Based on the finite element model proposed in this paper,the effects of wall frame constraints,wall height/thickness ratio and block strength grade on the seismic behavior of the filled wall are studied from the perspectives of wall deformation,stress development process,wall bearing capacity and stiffness.(5)Flexible connector design recommendations.Based on the research in this paper on the influence of the constraint conditions of the wall frame on the seismic behavior of the filled wall frame in and out of the plane,the preliminary Suggestions for the design of flexible joints in engineering are put forward in the conclusion.