| The prefabricated structure is an industrialized construction production method,and it is also the main form for the state to promote the structural adjustment of the construction industry.Compared with the common cast-in-place structure,the assembly structure has the advantages of less labor demand,less construction waste and short construction period.It has attracted more and more people’s attention.In this paper,different connection methods of prefabricated frame at home and abroad are summ,arized,and a connection scheme of prefabricated frame is proposed by using angle steel of concealed corbel.The prefabricated column with concealed corbel and the prefabricated notched beam are connected with the bottom steel plate through the top angle steel by using high-strength bolts as a whole,and the The experimental study and theoretical analysis on the seismic performance of prefabricated connection specimens are carried out.The main research contents and achievements are as follows:(1)The Low cycle reciprocating loading test of one common cast-in-place specimen and three prefabricated frame beam column concealed corbel angle steel connection specimens was made and completed.The whole failure process and failure characteristics of each specimen were obtained,and the seismic performance indexes such as hysteretic curve,skeleton curve,rigidity degradation,energy consumption capacity and displacement ductility of the specimen were analyzed.This paper mainly studies the influence of connection angle steel rib and angle steel thickening on the prefabricated specimen.The results show that the increase of additional ribs can improve the ultimate bearing capacity;The increasing thickness of angle steel can significantly improve the ultimate bearing capacity of the specimen,which can slow down the development of the specimen cracks,the time and ductility of the specimen to reach the ultimate bearing capacity are affected to some extent.(2)Through the experimental comparison and analysis of the ordinary current pouring test parts and prefabricated assembly connection test pieces found that the prefabricated assembly connection test pieces in the low-cycle reciprocating load effect has a high carrying capacity,in the connection angle steel side with the angle steel additional ribs and angle steel thickening to change its carrying capacity can basically reach the load capacity of the current pouring,and in the steel cover plate connected side of its carrying capacity is lower than the current pouring test piece;The displacement coefficient is greater than 3.0,which indicates that the assembly connection test piece has better ductility,increases the thickness of the angle steel and the additional ribs can improve the carrying capacity of the test piece,also improves the energy consumption capacity of the assembly connection test piece,slows down the stiffness degradation,especially increases the angle steel thickness can significantly improve the carrying capacity of the assembly connection test piece and reduce the damage of the dark bull leg in the pre-load.(3)Through the overall force analysis of the prefabricated frame beam-column covered bracket angle steel connection specimen,the tensile-compressive bar model and the shear friction theory are used to analyze and study the reinforced concrete dark corbel in the connection,and the corresponding configuration is introduced Reinforcement calculation formula;at the same time,the stress analysis of the gap beam in the prefabricated frame beam-column dark corbel angle steel connection is carried out,and the relevant calculations of the 6 possible failure modes in the gap beam are calculated.For the selection of connecting angle steel and high-strength friction type bolts in the test piece,relevant calculation methods are given according to the specifications. |
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