Experimental Study On Seismic Behavior Of A New Type T-shaped Section Prefabricated Shaped Column

Prefabricated building is the development direction of building industrialization,which accords with the concept of green environmental protection and sustainable development.Based on the previous research,the steel-encased concrete composite T-shaped cross-section special-shaped column is developed into an prefabricated structure.A new type of T-shaped section prefabricated shaped columns are presented.,and study on its seismic performance.In this paper,a total of 5 T-shaped section prefabricated shaped columns were designed and tested under seismic load by using the pseudo-static test method.Taking axial pressure ratio,stud length and steel ratio as test parameters,the development process and failure mode of cracks,hysteretic loop curve and skeleton curve,ductility,energy dissipation,capacity degradation,stiffness degradation and other seismic performance indexes of each specimen were obtained through the test.On the basis of summarizied the failure law of the specimen,the failure mode of the T-shaped section prefabricated shaped column n is extracted and its force transfer mechanism is analyzed.In addition,based on the experimental data,the restoring force model of T-shaped section prefabricated shaped column is established by fitting method.Through research and analysis,the following conclusions are drawn:1)The assembly joint worked normally during the test,the failure occurred in the test column,which proves that the assembly connection mode is feasible.2)As the axial compression ratio increases,the ductility of the specimen decreased.,as well as the elastic-plastic deformation ability is weakened and the stiffness degrades rapidly,while the form of hysteretic loop curve is still full,with better energy dissipation capacity and better seismic performance.3)Long studs be used within a certain height range of the column bottom,the energy dissipation capacity of the specimen is improved and the degradation of the bearing capacity is small,which can improve the seismic performance of the specimen to a certain extent.4)Increasing the steel ratio can improve the ductility of specimens,increase the ultimate bearing capacity of components and reduce the degradation rate of bearing capacity,the equivalent viscous damping coefficient is also increased,as well as the degradation of stiffness is delayed,which can improve the the overall mechanical performance of the specimen.5)The reinforced concrete of the web before cracking of the specimen transmits horizontal load by shear plate mechanism,while the reinforced concrete of the webs after cracking transfers horizontal load through multiple diagonal plates.After the structure reaches the peak load,the horizontal bearing capacity of the structure decreases rapidly due to the crushing of the web reinforced concrete slabs and the slippage of the original cracks.6)The T-shaped section prefabricated shaped column basically conforms to the assumption of the plane section,the channel steel and concrete have good cooperative working ability.7)The restoring force model established on the basis of the test can basically be consistent with the skeleton curve obtained by the test.