Study On Shear Bearing Capacity Of Bottom Of Prefabricated Wallboard And End Of Composite Beam

Prefabricated building is an important direction of green building development,However,China's prefabricated buildings started late,to promote the application of assembled structure in China,many scientific research theories and technologies are needed.At present,precast beam and precast wallboard are the most widely used components in practical engineering,the connection between prefabricated components and the assembly of prefabricated components and cast-in-place components is an important part of the transmission force of the structural system.In this paper,the shear strength of the horizontal joint at the end and bottom of the prefabricated composite beam is studied,numerical simulation analysis based on ABAQUS finite element for the design of composite beam and prefabricated wall.The following conclusions are drawn through simulation:The composite beam components are simulated and analyzed from two factors:the different position of the end key slot of the composite beam(0 times ho,1.0 times ho,1.5times ho)and the angle of the end groove(30~o,45~o,60~o).The simulation results show that:The farther the key slot is from the joint,the higher the shear capacity of the member is,The bearing capacity of the key slot joint is 13.7%higher than that of the close joint when the key slot is 1.0 times the effective beam height,when the key slot distance node is greater than the effective beam height,the increase of shear capacity of specimen is very small.The groove angle of beam end is between 30~oand 60~o,The smaller the angle,the higher the shear capacity,at the same time,stirrup has a great effect on the shear resistance of inclined section.The prefabricated shear wall components are simulated and analyzed from four factors:the change of the diameter of the through longitudinal reinforcement(C12,C14,C16),the arrangement of the through longitudinal reinforcement(middle single row arrangement,plum blossom arrangement,double row arrangement),the change of the axial compression ratio(0.3,0.4,0.5,0.6),and the change of the thickness of the grouting joint at the bottom of the wall(15mm,20mm,25mm,30mm).The simulation results show that:With the increase of reinforcement ratio and axial compression ratio,the shear capacity of prefabricated wall increases gradually.With the increase of the same reinforcement ratio,the bearing capacity of large-diameter reinforcement is higher.The thickness of the grouting layer of the horizontal joint at the bottom of the prefabricated shear wall has little effect on the shear bearing capacity,and the bearing capacity is relatively highest when the thickness is about 25 mm.In this paper,the shear resistance formula of the horizontal joint at the bottom of the precast concrete shear wall in each code is also compared and analyzed,The formulas are calculated numerically,The calculated value is compared with the simulated value,It is suggested to adopt the calculation formula of the bearing capacity of the horizontal joint at the bottom of the shear wall in the national installation regulations.