The Seismic Behavior Research On Partially Encased Concrete Column-steel Beam End Plate Connections

The partially encased concrete composite structure has many advantages, such as high construction speed, low cost, and the beam-column joints are easy to handle. It has been used in engineering abroad. In recent years, the related research at the initial stage has started in our country. The end plate connection is a typical semi-rigid connection. There is more research on the end plate connections of steel structures in domestic and foreign, but the research data for the end plate connection of welding H steel partially encased composite structure is fewer. The awareness of its mechanical properties, failure sequence, failure modes is still vague. Therefore, in order to clearly understand its seismic performance and failure mechanism, the research for the end plate connection joints of the partially encased concrete composite structure has important theoretical and engineering significance.This article has carried on the cyclic loading test of six end plate joints connecting the partially encased concrete composite column and steel beam, the effect of end plate thickness, the width-to-thickness ratio of column flange, added back plate structural on the performance of the joint connection were discussed. Through analysis of measured data and observing the destruction of the specimen testing procedures, the skeleton curves, bending moment-rotation hysteretic curves, stiffness degradation curves, shear deformation curves, strain distribution in the key parts and other test result on the6specimens are obtained. Analysis of the hysteretic behavior, ultimate strength, stiffness degradation, ductility, energy dissipation capacity and other relevant seismic performance indicators are carried. Based on the experimental study, the failure mode of the end plate joint connecting the welded H steel partially encased concrete composite column and steel beam is the beam flange and web buckling and form a clear plastic hinge, end plate rupture, flange buckling tearing on the core area of the column. The thickness of end plate and column flange width-thickness ratio is the key factor to affect the node bearing capacity, seismic performance. The bending bearing capacity of nodes increases with the increase of the thickness of the end plate, and the decrease of the column flange width-thickness ratio. The end plate thickness increased from12mm to18mm,24.66%increased in total energy consumption. That increased from18mm to24mm, the total energy consumption increased by7.65%; The average effective limit angle of all the nodes in test is larger than or close to0.03rad. The ductility factor of the displacement angle is from3.38to6.50and the6designed specimens have good ductility.In this paper, on the basis of experimental research, the end plate connection specimens is simulated by using the large finite element analysis software ANSYS. The three-dimensional finite element model of the test is built, the simulation results are in good agreement with the test. To make up for the test problems, considering a parameter variation for the thickness of end plate, column flange width-thickness ratio, the bending bearing capacity of end plate connection specimens is simulated. Via the experimental study of this paper, the conclusion can be useful for the national relevant standards and guiding design of engineering.