Study On Static Behavior Of Crisscross Plate-end Plate Joint Between Steel Box Modules

In recent years,China has vigorously developed prefabricated buildings to promote the industrialization of construction.Box-type modular buildings have attracted more and more scholars’ attention because of its high assembly rate,green,environmental protection,disassembly and other advantages.The existing research results at home and abroad mainly focus on the overall performance of modular buildings,but limited research has been done on the mechanical behavior of the connections of modular buildings.Although scholars at home and abroad have proposed a variety of modular steel building joints,but these joint forms are difficult to be used for the connection between functional modules of finished products.In this paper,a new type of crisscross plate-end plate joint suitable for finished box module connection is proposed by referring to the existing joints of modular steel building and considering the existing joints research results.In order to study the static behavior of the joint,three groups of tests,namely,axial compression tests,axial tension tests and bending tests,were carried out to obtain the bearing capacity and failure modes of the joint under different loading conditions.The reasonable finite element models of the joint are established by ABAQUS,and the main factors affecting the static behavior of the joint are analyzed,including the thickness of crisscross plate of the joint,the thickness of end plate of the joint,height of crisscross plate of the joint and the thickness of the column wall.(1)The failure modes of the joint under axial compression are divided into three types: torsional failure of crisscross plate of the joint,buckling failure of column end and combined failure of the both.The failure mode is related to the ratio of the thickness of the crisscross plate to the thickness of the column wall.The thickness of crisscross plate of the joint and the thickness of the column wall are the most important factors affecting the axial compression performance of the connection.The diameter and the location of construction holes have no obvious influence on the axial compression performance of the connection.(2)The failure modes of the joint under axial tension are divided into two types:the failure of bolt holes in end plate of the joint under tension and combined failure of bolt holes in end plate of the joint and end of columns under tension.The thickness of end plate of the joint will affect the failure modes of connection under axial tension.The thickness of horizontal plate is the most important factor affecting the axial tension performance of the connection.The diameter of bolts has no obvious effect on the axial tension performance.The thickness of end-plate and wall of columns have little effect on the axial tension bearing capacity,but it has obvious effect on the initial tensile stiffness.(3)The bending failure mode of the connection is that the plastic hinge are formed at the end of the beams.The height of floor beam and ceiling beam and the ratio of axial compression are the most important factors affecting the flexural behavior of the connection.The thickness of crisscross plate of the joint and the height of crisscross plate of the joint have no obvious influence on the flexural behavior of the connection.It is suggested that in practical application,the thickness of crisscross plate of the joint can only meet the requirements of vertical bearing capacity,and the height of crisscross plate of the joint should be 180 mm.