Study On Connection Of Prefabricated Profiled Steel Sheet And Concrete Composite Slab And Mechanical Behavior Of Joints

With the rise of labor cost,the requirements of energy conservation and environmental protection and the further clarification of national policies,Chinese prefabricated buildings have reached a rising stage of development.The joint between prefabricated members is the key of the whole prefabricated structure,which plays the role of load transfer and distribution.At present,the research on prefabricated profiled steel sheet concrete composite slab is very inadequate.The splicing of composite slab is mainly welding.The composite slab and other structures are connected by cast-in-place method.There are many wet operations on site,so the construction quality and progress are difficult to guarantee.Therefore,it is necessary to develop a new type of joint to facilitate the assembly connection.In this paper,four splicing forms of full-thickness composite slabs and half-thickness composite slabs were proposed.Two splicing forms of composite slabs based on concrete post-pouring bands,six types of prefabricated connections of slabs and beams,and two types of prefabricated connections of slabs and beams as a whole,five splicing forms of prefabricated composite slabs and concrete beams,and five splicing forms of prefabricated composite slabs and concrete walls were described.The component fabrications and installation methods for each new type of node have been described.The overall force analysis of the new joints was carried out,and the main force-transmitting components and structures,namely bolts,fillet welds,studs,flange plates,steel embedded parts and tenons,were emphatically analyzed and calculated.The formulas for calculating the bending and shear bearing capacity of the joints were established.Using ABAQUS finite element analysis software,the bolt joint of prefabricated composite slabs,the flange plate-bolt connection of prefabricated composite slab and steel beam and the cast-in-situ structural model under the same conditions were established respectively.The calculated results were in good agreement with the theoretical calculations.The analysis results showed that the bearing capacity,deformation capacity and ductility of prefabricated composite slabs with bolted splices were higher than those of cast-in-situ composite slabs under the same conditions.The thickness of composite slabs had the greatest influence on the mechanical properties of structures.When the thickness of composite slabs increased from 150mm to 180mm,the yield load and ultimate load increased the most,32.26%and 29.95%respectively.The thickness of profiled steel sheet,concrete strength,bolt spacing and thickness of connecting steel plate also had influence on the mechanical performance of the structure.The design suggestions for each parameter were put forward.The bearing capacity and deformation capacity of the connection between composite slab and steel beam with flange plate were slightly lower than the cast-in-situ structure under the same conditions,and the thickness of composite slab had the greatest influence on the bearing capacity of joints.When the thickness of composite slab increased from 150 mm to 200 mm,the yield load and ultimate load increased the most,which were 25.08%and 17.00%.The number of studs,the length of composite slab,the number of bolts and the thickness of flange plate also had an effect on the bearing capacity and deformation capacity of the joint.The comparison and analysis of each design parameter were carried out in order to optimize the structure.