Experimental Research On A New Type Of Inclined Column Transfer Structure Under Axial Compression Ratio

The oblique column transformation is a kind of conversion structure that has arisen in China in recent years.Compared with the traditional beam conversion,the oblique column conversion can effectively save the net height,the transmission path is more clear,and the building space can be utilized to a large extent.A form of structure worth promoting.Previous studies on the common oblique column conversion structure have shown that the conversion beam damage between the inclined columns is more serious,and it is more unfavorable for the structure to resist earthquakes.Therefore,a new type of structure of the new oblique column conversion structure is proposed.The new oblique column conversion structure refers to the built-in steel in the inclined column and the conversion beam,and is equipped with a certain force-reinforcing steel bar.Its function is to improve the bearing capacity of the structure through the internal steel,strengthen the ductility of the test piece,and avoid the conversion beam and the inclined column.Bigger damage.Since this is a new type of structural system,its force performance needs to be tested in depth.Based on the previous research groups,this paper uses experimental research and finite element simulation to study this new structure form,which lays a theoretical foundation for further promotion of the new oblique column transformation structure.The research results of this paper are as follows:(1)The low-cycle horizontal load test of the new inclined column-converted structural specimens under different axial compression ratios was carried out,and the experimental phenomena and strain changes of various components were described.A series of seismic performance indexes such as mechanical behavior,skeleton curve,hysteresis curve,stiffness degradation and bearing capacity degradation of structures under different axial compression ratios are studied.The test results show that the built-in steel and steel bars which embedded between the inclined column and the conversion beam can work well together.They delays the time of the yielding steel reaching the yield strain,enhances the ultimate bearing capacity of the structure,and the structural ductility also increases.When the specimen increases the axialcompression ratio,the ultimate bearing capacity of the specimen is improved,the ductility is decreased,and the stiffness degrades more rapidly as the cyclic displacement increases.(2)A formula for calculating the damage increment is proposed.At the same time,the 1st0 pt software is used to analyze the experimental data.Based on the damage,a three-fold line resilience model considering stiffness degradation is established.By regression analysis and analysis of the damage process,the hysteresis loop is divided into a hysteresis loop with a pinch point and no pinch point.At the same time,the numerical values of each characteristic point of the resilience model skeleton curve are calculated,and the specific calculation formulas of the performance index changes of the structure before and after the yield are derived,and the hysteresis rule corresponding to the restoring force model is established.The resilience model curve established in this paper is in good agreement with the experimental curve,which can provide reference analysis for this type of structural form.(3)Based on the test of the new oblique column conversion structure,the ABAQUS software was used to simulate it,and the failure mode,hysteresis curve and skeleton curve of the structure were compared and analyzed.The finite element simulation and experimental data are in good agreement,and the simulation method adopted in this paper is reasonable and effective.Combined with the finite element and experimental results,the weak point of the new oblique column conversion structure is located at the junction of the inclined column and the conversion beam,and the middle of the force transmission beam.The damage of the frame pillar and the inclined column column is not serious.The structural form conforms to the design concept of the beam: "strong column weak".