| Prefabricated buildings refer to buildings assembled on site with prefabricated parts.Prefabricated steel structures have become a national policy advocating development due to their light weight,efficient seismic performance,high degree of industrialization,energy saving and environmental protection,and short construction period,etc.At present,new structural systems and demonstration projects for prefabricated steel structures are constantly emerging on the market.However,the common shortcoming is that most of the joint connections still use the traditional welding-high-strength bolt hybrid type,which cannot be detachable.It leads to a serious impact on construction period and quality.This article is supported by the National Natural Science Foundation of China(51578357).The main research contents and conclusions are as follows:(1)Based on a large amount of literature review and investigation,emphasizing the advantages and disadvantages of the existing prefabricated steel structure building system and the scope of application.(2)A new system for prefabricated steel structure buildings is proposed.The main feature and innovation of the new system is to construct a new type of columnar node,which has no welding and only high-strength bolts,realizing 100% full assembly.(3)Through PKPM software for the design and analysis of this system,it was successfully applied to a demonstration project in Shanxi,showing the comprehensive advantages of the system,especially the amazing installation speed.(4)A unique structural design has been completed for this new type of stylobate base node.With the help of finite element analysis of ABQUS software,the excellent bearing capacity and seismic performance of the node have been verified.(5)For the M24 torsion-shear type high-strength bolts used in this new type of column base joint,the fatigue performance of the MTS Lankmark370.50 fatigue testing machine was used to test the fatigue performance,and the fatigue curve(S-N curve)was obtained,and its constant amplitude fatigue design method was established,which avoiding the hidden danger of fatigue damage。Besides,using Phenom scanning electron microscope to conduct macro and micro analysis of the fatigue fracture,revealing the mechanism of fatigue damage. |
