Theoretical Analysis On Structural System Of Prefabricated Light And Low Steel Frame Houses With Pinned Beam-Column Connections And New Gate-Shaped Braces And Its Mechanical Performance

In recent years, with the accelerated pace of urbanization, low-rise housing systems tend to diversify,but the high cost and the complex connecting member of most housing don’t meet the idea of building industrialization which China has strongly advocated and hinder its promotion. And owing to overcapacity on China’s steel production,development of steel structure housing is imperative. Therefore, the study of new prefabricated steel system is of great practical significance.In this paper, on the basis of light steel frame structure in rigid Beam-column joints, I propose a new architecture-Structural system of prefabricated light and low steel articulated frame houses with new gate-shaped braces(P-SFPG). The structural system uses a connection mode-columns keeping transfixion, beam end hinging on the pillar, and adding braces between columns.Construction site without welding and little wet work is in line with the requirements of the whole prefab.Horizontal lateral force is borne entirely by the support and vertical load is borne by the frame beams-columns.And because beam-column joints don’t deliver moments, which can greatly reduce the size of the beams and columns.Wherein the support includes not only general supports, but also new gate-shaped braces which are raised in order to solve the problems to open doors and windows.In order to study the mechanical performance of the new structure, this paper has conducted the following works:(1) To have verified the reasonableness of the proposed new gate-shaped support and the correctness of its equivalent model; To have compared the proposed new gate-shaped support with the general support and obtaining its superiority and inferiority; SAP2000 was used to study its failure modes-The results show that the first plastic hinge appears in the belowing struts of the new gate-shaped support and then in the topping struts,finally in the beams/which meets requirements of the first seismic fortification lines as are braces.And calculation formulas of the lateral stiffness of the new gate-shaped support.(2) To establish a two-layer overall P-SFPG house model and to utilize the midas to study its modal analysis,obtaining Self-vibration characteristics of the structure.Based on the above results,conducting response spectrum analysis under frequent earthquake and dynamic elastoplastic analysis time-history analysis under the rare earthquake to the model with SAP2000 to study the failure modes-The results show that there are excellent seismic performances in the model under the frequent earthquake and the rare earthquake,Which has a higher yield strength; the first plastic hinge appears in the belowing struts of the new gate-shaped support of the overall structure and then in the topping struts,which meets requirements of the first seismic fortification lines as are braces.(3) Based on the results of the above studies, The project,that has gotten the excellence rural residential seismic design scheme of Shandong Province,was redesigned by the approach of P-SFPG system.First the cross-sections of beams and columns are designed according to vertical loads and the cross-sections of braces are designed according to horizontal loads.Then the parts are assembled into the overall structure and to apply all loads and seismic action to this structure.To utilize the midas to conduct its Seismic Response Spectrum Analysis,studying Seismic performance of the overall structure.Finally,The preliminary budget of the house was compared with the masonry structural one - The results show that the approach of the elements section which were designed respectively is reasonable;the resistance to lateral displacement and seismic performance of the assembled overall structure is excellent;And the amount of steel consumption significantly is less than other light steel structure and its economic performance is in the reasonable range.The study showed that the new architecture under the dimensions of the beams and columns which are rational designed can reflect the good mechanical properties;while the lateral stiffness formula of its accompanying new gate-shaped support is reasonable;Failure mode meets requirements of the first seismic fortification lines as are braces;and the economy characteristics of the overall structure is good, suitable to be promoted vigorously.