Study On Mechanical Properties Of Steel Structure Joint Of New Type Modular Box Building

With the continuous improvement of global science and technology,construction industrialization has been further promoted.Boxed modular buildings are made of box-like components as structural system and assembled in the way of building blocks on site.The characteristics of high integration degree,efficient on-site installation and green environmental protection have been rapidly developed.Compared with traditional labor-intensive housing construction,modular building has obvious advantages,which can speed up construction,reduce cost input,effective quality control,reduce manpower demand,and flexible space layout.Due to the particularity and difference in the structure of modular cartridge joints,there are still some difficult problems to be solved in the practical application.First,the research on the performance of modular cartridge joints is not mature enough,and there are few researches on the static performance and dynamic analysis of modular cartridge joints.Second,there has not been a reasonable node structure,not only can be quickly and easily assembled on the site,but also can meet the overall stability of the structure,bearing capacity and seismic capacity,resulting in modular building difficult to use in high-rise and high seismic fortification areas.This paper presents a new type of modular building steel structure joint design,and analyzes its mechanical properties,hoping to promote the development of modular building box.First of all,this paper proposed a fine modeling and numerical analysis method through finite element software ANSYS Workbench to set the material constitutive relationship,contact definition,bolt pretension force application method and solution method.In order to verify the accuracy and rationality of this analysis method,the numerical analysis method used in this paper is adopted to establish the same model and parameter setting as the test.The results are compared and analyzed,which verifies that the technical analysis method in this paper can accurately simulate the real stress condition of modular nodes.Secondly,the mechanics properties of the modular nodes in the system analysis,through the study of this node in the in-plane shear,out-of-plane shear and flexural bearing capacity under the mechanical properties,analysis of node failure mechanism,stress distribution and development trend,the bearing capacity and stiffness degradation performance indicators,such as the research results show that the node has a good ability of bearing capacity and deformation.Then,the seismic performance of the joint under low cyclic action is studied.The results of hysteresis curve show that the joint has good ductility and energy dissipation capacity,which indicates that the joint can be more reasonably used in high-rise buildings and seismic fortification areas.Finally,the mechanical performance of the modular joint under the influence of different parameters is analyzed,and the optimization design of the joint is proposed.Parameter analysis results show that the bearing capacity and ductility of modular joints will be reduced by increasing the axial compression ratio.Appropriately reducing the thickness of the connecting plate can make the upper and lower modules code form and effectively improve the bearing capacity of the joints.When the wall thickness of rectangular steel pipe is reduced,the failure of joints will be aggravated,and the overall stiffness will decrease quickly.