Simulation And Full Scale Model Experiment Of Mechanical Properties For Replaceable Steel Structure Joint

The design of prefabricated steel structure buildings originated in Europe and America,of which the construction methods and mechanical properties have been widely concerned by researchers.Compared with traditional structures,the prefabricated steel structure has the advantages of flexible space arrangement and high degree of integration.The development of prefabricated steel structure is in accordance with the trend of building industrialization in the new era.For the assembled steel structure,the most important is the joint connecting each component.The quality and performance of joint will directly affect the safety of the whole structure.In recent years,with the introduction of the concept of resilient city,more and more scholars pay attention to the low damage and recoverable performance of structures under earthquake,and began to study the replaceable steel structure joints.In this paper,based on the concept of "structural fuse",a kind of replaceable steel structure joint is proposed.A series of theoretical calculations,full-scale model tests and finite element simulation analysis are carried out on the replaceable steel structure joint.The mechanical properties of replaceable steel structure joints after earthquake are obtained.The main research contents are as follows:(1)The structure and preliminary theoretical design of replaceable steel structure joints after earthquake have been completed.The steel beam and steel column are connected by three parts of gussets.The upper and lower T-shaped energy-dissipating gusset participate in energy dissipation during the earthquake and take the lead to enter plasticity and then destroy.The middle scissors plate and the pin provide vertical supporting force for the steel beam.Steel beam,steel column and the middle gusset are all in elastic state during the whole earthquake process.After the replacement of the damaged components,the structure can quickly recover its function.(2)Full-scale model experiment of the proposed replaceable joints was carried out.Three groups of typical full-scale models of steel frames were designed based on the length of the energy-dissipating section,and the experimental studies under monotone loading and low cyclic loading were completed.The mechanical properties of the replaceable joints was summarized by observing the experimental phenomena and analyzing the experimental results.(3)Finite element simulation of replaceable steel structure joints based on ABAQUS was completed.Several groups of finite element models were established for numerical analysis.By comparing with theoretical calculation and full-scale model test results,the influence of the length of energy-dissipating section on the mechanical properties of joints was further studied.(4)A design method of replaceable steel structure joints after earthquake is proposed based on the principle of flexural and plastic double prevention.The buckling analysis ensures that no local buckling occurs before the energy dissipating parts reach the ultimate state,and the damage time sequence design ensures that the main structure does not enter the plastic state during the earthquake process.Through a series of research results show that the reasonably designed replaceable steel structure joints have excellent bearing capacity and energy dissipation capacity.The proposed joint can be used as "structural fuse" to ensure the safety of the main structure during the earthquake,and it also has the advantages of rapid and convenient construction,controllable construction quality.