Study On Seismic Performance Of Square Steel Tubular Frame Structure Filled With Friction Energy-dissipating Particles

As one of the most active earthquakes in China,Yunnan Province has suffered from frequent earthquakes and rare earthquakes.Earthquake damage is sudden,strong,random,and wide-ranging,and the secondary disasters are not to be underestimated.Earthquake disasters have brought great threats to personal safety and social economy.This situation is particularly noticeable in the underdeveloped areas of Yunnan where earthquakes occur frequently.The economic conditions in underdeveloped areas are backward and they are unable to consider the seismic capacity of the building structure.Therefore,they suffered from large economic losses and security threats during the earthquake.Therefore,this paper considers the local conditions,based on the principle of low cost,easy construction and good earthquake resistance,designs a frame structure of square-filled square steel tube and analyzes its seismic performance.First,for the underdeveloped areas,civil steel structures are designed according to the site type,seismic design grouping and related engineering background,and a finite element model is established.The design structure meets the relevant design and seismic specifications,indicating that the structure is consistent with the actual working conditions,and has the conditions to guide the laboratory test for the later analysis and comparison with the grain-filled square steel pipe frame.Based on the similar model theory,test specimens were designed to control the applied loads and related parameters.Secondly,the selection of the particle filling material,in accordance with the concept of low cost,easy construction,easy to obtain,the selection of graded gravel and guava stone as a particle filling material.The grading test,the crushing value test and the needle-like particle content test of the graded crushed stone and the guillotine are carried out,and the category is judged.According to the test result,the better grading and the better crushing value and the needle-like shape are selected.Particle content of the material.The shear friction energy consumption test was carried out on the selected graded gravel and guava stone,and the energy consumption capacity was analyzed.The test results show that the energy consuming capacity of the granular material is mainly related to the classification of the particulate material,the displacement amplitude and the vertical load,and is positively correlated with the displacement amplitude and vertical load.Among them,in the shear friction energy consumption test of granular materials,a special device for the test,a shearing energy consumption test device for granular materials,was designed.The device can better simulate the movement of the granular material inside the square steel tube cavity,and it is convenient to replace the filler to apply the vertical load,which greatly improves the test efficiency and the research cost.Then,the low-cycle repeated loading test(i.e.,quasi-static test)of the particlefilled square steel pipe is carried out,and the initial sliding force,initial stiffness,equivalent stiffness,energy consumption capacity and failure mode of the other steel pipe are analyzed.The results show that the failure process of square steel tube filled with granular material and unfilled granular material is four stages,namely small deformation stage,large deformation stage,rapid deformation stage and fracture failure stage.However,the fracture failure stage of the square steel pipe after the particle filling is later than the unfilled square steel pipe,indicating that the particle filling material improves the failure process of the square steel pipe.The analysis of the skeleton curve and hysteresis characteristic curve of the other steel pipe shows that the rigidity and energy consumption of the square steel tube after the particle filling are improved.Finally,The construction technology of particulate filled square steel pipe was improved,bolts were welded in its cavity,and seismic simulation shaking table test was carried out.The test results show that the construction technology improves the dynamic characteristics and dynamic response of the structure,and effectively improves the seismic performance of the structure.the test parameters of the particlefilled square steel tube were reduced to the structural model.The seismic performance of the particle-filled square steel-steel frame structure was improved by comparing the inter-layer displacement angle.It shows that this measure improves the seismic capacity of the structure.