Research On The Performance Of A New Type Of Prefabricated Connection With Cantilever Beam Segment

In this paper,a new type of prefabricated connection with cantilever beam segment is proposed based on the splicing connections with cantilever beam segment and end plate connection in the specification.A new type of basic specimen was designed.Based on the basic specimen,parametric studies were conducted through the change of thickness and width of the end plate,the number of bolts on cover plates for splicing and end plates in the splicing zone,the thickness of the end plate,the length of the cantilever beam,which means the distance between the beam-to-column joint and the splicing position,the axial compression ratio of the column,the magnitude of pre-tension force in high-strength bolts,and the friction coefficient between the contact surfaces.In parametric studies,8 groups of specimens were designed to test the aforementioned parameters.The nonlinear finite element method was applied to study the performance of the specimens of different parameters under the monotonic and hysteretic load cases.After that the comparisons was made between the proposed new connection and the traditional connections.Following conclusions were drawn through above studies:(1)Under monotonic load cases,the thickness of the cover plate has the greatest influence on the bearing capacities of the specimens,following by the thickness of the end plate in the splicing zone,the width of the cover plate has the slightest influence on the bearing capacities With respect to the rotational deformation in splicing zones,the thickness of the cover plate take the first place again,following by the width of the cover plate,the thickness of the end plate has almost no influence on that.(2)Under hysteretic load cases,the thickness and width of the cover plate,the number bolts on cover plate,and the length of the cantilever beam have significant influence on the hysteretic behavior of specimens.When the number of bolts in the splicing zone cover plate is less,the hysteresis curve of those specimens have reduced pinch phenomenon,and the specimens show poor energy-dissipating capacity.The thickness and width of the cover plate have significant influences on the hysteretic behavior of the specimens,which leads to the recommendation that the cross-sectional area of the cover plate should be larger than the area of the beam flange in spliced zones.The ratio of cover plate cross-sectional area to the cross-sectional area of the beam flange in spliced zones should be controlled between 1.2 and 1.4,and the thickness of the cover plate should not be less than the beam flange in spliced zones.The length of the cantilever beam has a significant effect on hysteresis behavior of the specimens.Through the analysis,it is recommended that the splicing position should be set near the inflection point of the beam,but the length of the cantilever beam should not exceed 1.6 m.The thickness of the end plate in the splicing zone has little influence on the hysteresis performance of the joints.In order to fully develop the plasticity of the plates,The thickness should be limited to 6-10 mm.The axial compression ratio of the column,the magnitude of pre-tension force in high-strength bolts and the friction coefficient between the contact surfaces have nearly no effect on the hysteretic behavior of the specimens.(3)Under hysteretic load cases,the bearing capacity of the new type connection is about 8% higher than that of the traditional connections.Compared with the traditional connections,the new type of connections have better energy dissipation capacity.