Research On Mechanical Properties Of Splice Joint Of Modular Quasi Frame Structure

With the development of economy and technology,the prefabricated buildings are playing an increasingly important role in improving social efficiency,solving the shortage of labor force,and protecting the environment.As a form of assembly with the highest assembly rate,modular buildings once again enter the public’s view.Modular buildings are an integrated buildings formed by many room-sized modular units which are prefabricated in the factory.Since almost 90% of the processes are completed in the factory,the modular buildings has the characteristics of high construction speed,less on-site construction work,and less environmental pollution,however,the restrictions of transportation and hoisting,plane layout,joint connection and structural integrity restrict the development of modular buildings.On the basis of predecessors,this paper proposes a new splice joint of modular quasi frame structure。The module joint can be divided into single column splice joint,double column splice joint,three-column splice joint and four-column splice joint according to the location of the column.In this paper,the primary mechanical properties of the four types of module joints are studied.Firstly,the static performance analysis and hysteresis performance analysis of these four kinds of joints are carried out through ABAQUS software.The static analysis results show that the failure modes of the double column splice joint,the three-column splice joint,the four-column splice joint are basically the same as the single-column splice joint.The specific performance is as follows: loading from the major axis,the web of universal column firstly yields and destroys;loading from the minor axis,the flange of universal column firstly yields and destroys.The hysteretic analysis results show that the hysteresis curves of the four types of joints are relatively full,and their energy dissipation capacity is strong,and the ductility performance is good.geometrically,the double column splice joint,the three-column splice joint and the four-column splice joint are a simple copy of a single-column splice joint,but their ultimate load increasing multiples were greater than the geometric multiples due to the integrity of the joint.Then,through the analysis of four parameters of column axial compression ratio,column web thickness,column flange thickness and column end opening of single column joint,the paper concludes: as the column axial pressure ratio increases,the major axis ultimate bearing capacity of the joint increases first and then decreases,and the minor axis ultimate bearing capacity of the joint decreases gradually.As the thickness of the column webs increases,the major axis ultimate bearing capacity of the joint increases gradually,and the increase is obvious.As the thickness of the column flange increases,the ultimate bearing capacity of the joint increases gradually and becomes more obvious.With the decrease of the opening diameter,the major axial ultimate bearing capacity of the joint increases gradually,but the increase is small.Finally,by comparing the internal forces and displacements of the ABAQUS-based multi-scale finite element model and the simplified model based on SAP2000,this paper concludes that the internal forces and vertex displacement of the model which are modeled using the simplified connection method A(hinge)and the simplified connection B(hinge)are accurate and can meet the engineering design requirements.