| As a high-quality product derived from the development of building industrialization to a certain extent,box-type modular buildings have significant historical development opportunities and broad development prospects.However,the use function of traditional modular steel structure houses is only limited to living and offices.Therefore,under the support of market demand and technology,a new modular low-rise box-type steel structure shared fitness bar system that can meet people’s daily fitness and exercise needs came into being.However,the joint structure,joint mechanical properties,and overall mechanical properties of the structure are not completely clear.To ensure the safety of the structural system and its application in practical engineering,it is necessary to conduct in-depth research on the structural system.The main research contents of this paper are as follows:(1)The design background and design scheme of the modular low-rise box-type steel structure shared fitness bar system are introduced,and three connection node forms suitable for the structural system,including two-box nodes,four-box nodes,and eight-box nodes,are proposed,and the node structure is introduced in detail.The section design of the beams and columns of the modular unit frame is made of square steel pipes,which makes the structural system have better rigidity and bearing capacity than the traditional modular building;the bolts are designed to be submerged due to the existence of the inner nested cylinders,which makes the surface of the joints better.Keep it flat for easy wall installation.(2)The refined models of two-box nodes,four-box nodes,and eight-box nodes were established using the finite element analysis software ABAQUS,and the accuracy of the models was verified by experiments.The mechanical properties and failure mechanism of three kinds of joints are studied,the whole process curve of load-rotation angle is given,and the bending stiffness and ultimate bearing capacity of joints are also given.The research shows that the ultimate bearing capacity and stiffness of the two-box,four-and eight-box nodes proposed in this paper are 95%and 90%of those of the rigid-connected nodes,respectively.To facilitate the analysis of the overall model of the shared fitness bar,a simplified calculation model of the rod system-spring connecting the nodes is proposed,and the local box model is used to check the calculation accuracy of the simplified node model.(3)Using the node simplified calculation model proposed in this paper,the overall model of the modular low-rise box steel structure sharing a fitness bar with standard and upgraded specifications are established,and the structure is structurally analyzed.The calculation results show that all mechanical performance indicators are within the specification limits.Inside.The joint model and the rigid joint model of the overall structure of the shared fitness bar with two specifications are established,and the performance of the joint is analyzed by comparing the design indicators such as the deformation and stress of the actual joint model,the joint model,and the rigid joint model.(4)The time-history response analysis of small earthquakes and large earthquakes is carried out on the modular low-rise box-type steel structure shared fitness bar of standard and upgraded specifications,and the seismic performance of the structure is studied.The shared fitness bar adopts three types of rigid joints,hinged joints,and actual joints Model.The results show that under the action of 9 degrees earthquake,the interlayer displacement angle of the system is less than the specification limit,and it has good seismic performance. |
