Research On The Dynamic Performance Of A Fabricated Lightweight Steel Structure System

The assembled lightweight steel structure is mainly suitable for buildings below five floors.The assembled lightweight steel structure is still in the initial stage of development in China,and several structural forms are almost completely referenced abroad.Our group has proposed a fabricated ceramsite concrete-light steel structure system,which has been applied in five 1 to 3 storey buildings.Based on the previous research,this paper discusses the dynamic performance of this new type of structural system.The quasi-static performance of cold-formed thin-walled steel ceramsite concrete composite wall is studied.The finite element numerical simulation analysis of the low-cycle reciprocating cyclic loading of the non-hole composite wall,the non-hole plus cross-shaped cross-supporting composite wall and the open-wall composite wall,from hysteresis curve,skeleton curve,ductility coefficient and energy consumption Analyze the angles to find the law of force.The results show that the wall-free and cross-shaped cross-support composite wall has the best seismic resistance.When the project is applied,the opening size of the composite wall should be reasonable and appropriate,and the opening rate should be less than 40%.Otherwise,the wall,especially the periphery of the hole,should be strengthened.The finite element model of this kind of structure was established by ABAQUS,and the vibration mode and natural frequency characteristics were analyzed.Parametric analysis was carried out to study the effects of different factors such as the thickness of the cold-formed thinwalled steel,the strength of the ceramsite concrete,the thickness of the wall,the joint of the joints and the type of oblique support on the natural frequency and fundamental frequency of the structure.The results show that the ceramsite concrete strength,wall thickness and joint connection have a great influence on the overall stiffness of the structure.The thickness of the cold-formed thin-walled steel section also has a certain influence on the overall stiffness of the structure,but it is not as obvious as the ceramsite concrete.The oblique support contributes less to the overall stiffness of the structure,and it is necessary to increase the number of oblique supports to increase the overall rigidity of the structure.The vibration mode decomposition response spectrum analysis of the low-level structure is carried out,and the seismic response under different seismic intensities is obtained,and compared with the light steel structure without considering the effect of ceramsite concrete.The results show that the seismic response of the new fabricated lightweight steel structure is relatively small,and the seismic performance can meet the design specifications.The dynamic time history analysis was carried out to analyze the dynamic response of the top-level acceleration,floor displacement,interlayer displacement angle and base shear force under the action of 7 and 8 degrees and rare earthquakes.The results of dynamic time history analysis considering and not considering the effect of ceramsite concrete are compared.The results show that the seismic response generated by artificial waves is the largest under the same seismic wave acceleration peak.The inter-layer displacement angle of the structure under the action of multiple encounters and rare earthquakes is smaller than the inter-layer displacement angle limit required by the specification,and the seismic performance of the structure meets the requirements.The analysis further shows that the ceramsite concrete contributes a lot to the overall stiffness and seismic capacity of the structure.The connection between the building(house)cover and the wall with a spacing of less than 600 mm can basically meet the seismic requirements.