Research On The Performance Of The Connection Node Of The New Type Steel Structure Modular Unit

The building formed by stacking and assembling modular units prefabricated in the factory with multiple functions is called modular building.Due to its fast construction speed,easy assembly,and low noise and dust pollution,the modular building conforms to the pace of development of industrialized buildings in the country.At present,it mainly focuses on the study of traditional buildings.The stress of modular building is different from that of traditional building,so this paper does the following research on steel structure modular buildings.First of all,the mechanical properties of various modular elements with different modular structures are analyzed.A total of six different types of modular units have been designed.The structural internal forces and deformations of different types of modular units are compared.The analysis shows that the mechanical properties of the modular unit can be effectively improved by increasing the center column,adjusting the spacing between nodes,adding diagonal webs,adding shims at the bottom of the column,and setting steel plate shear walls at the end span.Secondly,in order to explore the connection forms of modular unit columns for multi-storey and medium high-rise steel structure modular buildings,this paper proposes an assembly structure of L-shaped square steel tube modular columns for steel structure modular buildings after summarizing the connection joints of different structural forms.This node can be used in multi-story and high-rise buildings.By analyzing the force transmission path of this node,a simplified model of a new type of node is proposed.The simplified finite element model is established by software,and the analysis results of the model are compared with the finite element results of the physical node to verify that the node simplification is correct.Three groups of specimens are designed to study the mechanical properties of the new joint.Finite element analysis is carried out from the aspects of loading method,the presence or absence of axillary beams,and the height of the bottom beam to study the static and seismic performance of the new type of joints.Finally,in order to analyze the seismic performance of the multi-layer modular building with the above-mentioned new steel structure modular unit connection nodes,a four-story steel structure modular building is designed and the structural design is carried out by Sap2000.Comparing the analyzed model results with the requirements of the specification limits,the results show that the four-story modular building structure design is reasonable.The dynamic time history analysis of the designed modular building is carried out to analyze the seismic performance under different fortification intensity.The research shows that the parameters under frequent and rare earthquakes meet the requirements of the code and have good seismic performance.