Research On Seismic Performance Of Assembled Special-Shaped Steel Lattice Column Frame

Since 2015,China has begun to vigorously promote prefabricated buildings.Due to its flexible layout in space,it is simple and convenient in construction.Due to its light weight,easy handling,high standardization and simple processing,steel bars can be regarded as the most suitable materials for prefabricated buildings,and China is a large country with steel bars production,so steel structure prefabricated buildings have great application prospects and economic value.However,due to various reasons,the prefabricated steel structure started late in China,so there are many problems in the current prefabricated steel structure buildings: a large number of convex beams and columns,resulting in reduced use space;Various building specifications are not perfect,resulting in not widely promoted.In order to solve the above problems,this paper proposes a new type of special-shaped steel lattice column,which introduces H-shaped steel beam to form a new assembled special-shaped steel lattice column frame(SLCF).In this paper,the seismic design of SLCF system is studied.The main research contents and results are as follows :(1)In order to study the lateral resistance of assembled special-shaped steel lattice columns,four finite element models were established by using finite element software ABAQUS to carry out monotonic static pushover loading.The results show that the ultimate lateral bearing capacity and initial stiffness of cross-shaped special-shaped steel lattice columns are the highest.The bearing capacity of cross-shaped,T-3 and T-2 along the direction of three column limbs is 118.70 %,112.24 % and 18.41 % higher than that of L-shaped column,respectively.The buckling deformation of the batten plate dissipates energy,and finally withdraws from work with the excessive deformation of the square steel tube column.(2)In order to propose the optimal structural solution suitable for different storey heights of prefabricated steel structure residential buildings,the special-shaped steel lattice column is used to optimize the design of steel structure residential buildings.The basic design ideas of structural design and seismic performance-based design are proposed,and the corresponding seismic performance objectives for SLCF system are proposed.(3)In order to explore the dynamic characteristics of SLCF system,three SLCF models were established by MIDAS GEN for modal analysis and response spectrum analysis,and compared with the traditional steel frame structure.The results show that when the steel consumption is basically the same,compared with I-steel frame,the increase of SLCF system stiffness makes the weak layer of the structure move up and improves the seismic performance of the whole structure.SLCF system has better torsional stiffness and greater lateral bearing capacity,which is more conducive to structural seismic resistance.(4)In order to study the seismic performance of SLCF under rare earthquakes,the static elastic-plastic analysis and dynamic elastic-plastic analysis were carried out,and the seismic performance indexes such as bearing capacity,deformation and ductility coefficient were determined and compared with the traditional steel frame.The results show that SLCF system has high lateral bearing capacity and strength reserve,which is 1.13 – 1.49 times that of I-steel frame.With good ductility and energy dissipation capacity,the ductility coefficient of SLCF system is 4.56 – 6.25,which is 1.23 – 1.35 times that of I-steel frame;The yield mechanism of SLCF system is that the support yield first,then the frame beam yield,and finally the column yield.The whole structure is ductile failure.After SLCF system enters elastoplasticity,the components accumulate damage and the overall stiffness degenerates,but the model does not lose bearing capacity and collapse,indicating that the structural design meets the seismic performance target of rare earthquakes.