Seismic Analysis Of Semi-Rigid Joint And Its Application In Prefabricated Shear Wall Structures

With the rapid development of China’s construction industry,prefabricated buildings are receiving more and more attention due to their advantages of energy-saving and environment-friendly structure,green and efficient construction method,and high degree of industrialization.The existing research mainly focuses on improving the construction efficiency of prefabricated buildings and the overall mechanical properties of the structure,and there is a relative lack of research on the semi-rigid joints of prefabricated structures.Based on the existing research,this paper proposes a new type of prefabricated semi-rigid beam-column joint with section steel bolted connection,and applies low circumferential reciprocal load to the joint through ABAQUS to study its mechanical properties and force mechanism,and finally verifies the application of the joint on engineering examples through architectural design analysis software Yingjianke(YJK),the main research contents and results are as follows:(1)Based on the load calculation equations for semi-rigid nodal beams with the same rotational stiffness at both ends,the bending moment calculation equations for the general case semi-rigid nodal beams with different rotational stiffness at both ends under nodal rotation,nodal displacement,and general load on the beam are derived using structural mechanics theory,and the unit stiffness matrix of the semi-rigid nodal beams is also derived.(2)ABAQUS is used to simulate the low circumferential reciprocal loads on the new prefabricated semi-rigid beam-column joints and the traditional cast-in-place joints respectively,the differences in mechanical and seismic properties between the new joints and the cast-in-place joints were investigated.The results showed that:compared with the cast-in-place joint,the ultimate load capacity of the new prefabricated joint is 31.7%higher,the ductility is 7.23%higher,the energy dissipation coefficient of the joint is 13.8%higher;the joint stress nephogram derived from the finite element analysis shows that the comprehensive mechanical properties of the new joint are higher than those of the traditional cast-in-place joint.(3)In this paper,the influence law of axial compression ratio,concrete strength,reinforcement strength and strength of connectors on each performance of new prefabricated semi-rigid beam-column joints under low circumferential reciprocal load,including ultimate load capacity,ductility and energy dissipation level,are analyzed separately by ABAQUS finite element software.And the research results show that,with the increase of axial pressure ratio,the ultimate bearing capacity of the joint increases,while the joint ductility decreases,and the energy dissipation coefficient of the joint increases first and then decreases with the increase of axial pressure ratio;with the increase of concrete strength,the ultimate bearing capacity of the joint increases,but the joint ductility also decreases,and the energy dissipation coefficient of the member gradually increases;with the increase of reinforcement strength,the ultimate bearing capacity of the joint increases,the ductility increases,and the energy dissipation coefficient of the joint decreases with the increase of reinforcement grade;the strength of the connection has no obvious effect on the mechanical properties of the joint.(4)The seismic performance of the new prefabricated semi-rigid beam-column joints in the actual structure is analyzed by YJK structural design and analysis software,and it is found that the seismic load of the prefabricated structure with the new prefabricated joints had a smaller dynamic self-excitation period than that of the cast-in-place structure,and the torsional self-excitation period is slightly larger than that of the cast-in-place structure;the maximum displacement of the prefabricated structure under seismic load,the inter-story displacement angle,and the shear force at the bottom of each floor are all smaller than those of the cast-in-place structure.The overall energy dissipation capacity of the prefabricated structure is higher than that of the cast-in-place structure,but the energy dissipation capacity of the cast-in-place structure is comparable to that of the cast-in-place structure in the pre-earthquake period and is better than that of the prefabricated structure in a certain interval.