Seismic Behavior Analysis And Design Method Of New Fully Assembled Composite Steel Frame Structure

For it better meets the requirements of building construction and structural seismic performance,the Special-Shaped Column Frame Structures derived from multi-storey frame structures are gradually popularized in the multiple high-rise structures.However,due to the use of concrete structures in special-shaped columns,it is difficult to meet the social development goals of ?safe and efficient,green and environmental friendly? in the construction industry because of the large self-weight,heavy wet work,and low degree of assembly.In this thesis,special-shaped lattice columns(SLC)are used instead of special-shaped concrete columns to improve the assembly rate of the building;I-shaped corrugated web beams are introduced to enhance the seismic stability of the structure,thus a new type of assembled composite steel frame structure system(CSF)is proposed.At present,a series of researches towards the Special-Shaped Column and corrugated web I-beams have been conducted by scholars at home and abroad,but the research achievements are less in the both application of two components into steel-framed structure.And the research on the bearing capacity,failure mode,and hysteresis behaviour of the SLC and dynamic characteristics of CSF structural system under earthquake action is still scarce.Therefore,the study about aseismic behavior of CSF is of great practical significance.To explore the lateral resistance performance of SLC,four kinds of SLC components were designed,according to the cross-sectional shape and stress characteristics of the component.And a finite element model was established by using ABAQUS analysis software,and a series of loading simulations were carried out.From monotonic static pushover loading in this four kinds of SLC,it can be known that: the cross-shaped SLC has the highest ultimate bearing capacity and the maximum initial stiffness.The bearing capacity of the cross-shaped SLC,the T-SLC-1 stressed along the symmetry axis,and the T-force applied along the asymmetric axis is 48.77%,43%,24.14% higher than L-shaped SLC,and the ductility coefficient is 19.6%,10.28%,9.04% higher.As T-shaped SLCs,the T-SLC-1 which is under stress along the axis of symmetry has an increase of 36.74% in ultimate bearing capacity and a ductility coefficient of only 1.36% increase compared with T-SLC-2 under stress along the axis of symmetry.At the initial stage of SLC loading,the buckling deformation dissipated seismic energy,and the stress development continued to extend to the node,and finally withdrew from work due to excessive deformation of the square steel pipe column.From the low-cycle repeated loading simulation results of the four SLCs,we can see that the hysteresis curve of the SLC is full,and the forward and reverse directions maintain high stability;the cross-shaped SLC hysteresis curve changes uniformly at each stage and the longest displacement time history is experienced which is demonstrates good ductility and energy consumption.To study the dynamic characteristics of the CSF structure system under earthquake action,the SAP2000 model for the CSF structure system was established by using the equivalent size data of SLC and corrugated web I-beam,and makes a comparation between the SAP2000 model and the RCSF structure.Shear wall(SW)was introduced to explore the seismic performance of the frame under the same lateral force resistance system of CSF and RCSF.The simulation results show that the maximum floor displacement angle of CSF system and RCSF system mostly appears in the 3-4 floors,and the deformation presents the characteristics of shear mode.The secondary torsional mode appears too early,and the acceleration curve and vertex displacement curve fluctuate greatly,which is not conducive to the seismic performance of the structure.The lateral displacement of CSF system is about 8.87% larger,and the initial stiffness is about 11.72% smaller than that of RCSF system.Under the action of an 8-degree earthquake,the floor displacement of each model structure increases continuously with the height of the floor.Compared with the CSF and RCSF systems,the floor displacement of CSF-SW and RCSF-SW is significantly reduced,the acceleration curve peak is increased,and the base shear is increased.The SW system performance is more obvious,the peak acceleration curve and the peak displacement curve have small and stable fluctuations,good ductility,and the best seismic performance.This subject analyzes the SLC lateral resistance performance and the dynamic characteristic of the CSF system under earthquake action,which is a supplement to the current special-shaped steel frame composite structure and provides a reference for further theoretical research and practical application.