Seismic Behavior Of PEC Column And Steel Beam Frame Connected With Top-seat Angle

The partially encased concrete composite columns (PEC column) is a new type ofstructures in recent years. That has obvious advantages compared with the steel structuresand the reinforced concrete structures, such as high bearing capacity, good plasticperformance, convenient production, great economic benefits and others. Top and seatangle connection has advantages of strong rotation ability, good ductility, convenientconstruction etc... So studying on the seismic performance of PEC column and steel beamframe connected with top and seat angle connections has theoretical and engineeringapplication value.Three one-layer single-span PEC column-steel beam frames connected with top andseat angle connection had been designed, which were carried on the low frequency cyclicloading. The key parameters were the vertical distance between the center of the screwhole in vertical limb connected with the column flange and the horizontal limb of theangle(Hereinafter referred to as the angle bolts margins) and the axial compression ratio.Through the test, the hysteresis curve and skeleton curve were achieved. The research ofseismic performance index and the strain on the control section were concluded. Theresults show that the failure characteristics of the model include that the concrete in thecolumn bottom was crushed, the tie bar was pulled off from the column weld, the plastichinge of the beam and column respectively appeared apart from the angel steel from4cmto8cm and above the column stiffener from5cm to15cm, interspace about from3to5mmappeared in the round edge of the angel. The hysteresis curves are full and the ductilitycoefficient is more than3.0, which shows that the composite frame of PEC column andsteel beam connected with the top-seat angle has a good ductility and energy dissipationcapacity. The axial compression ratio increases from0.25to0.35, the ultimate bearingcapacity improves about10.7%, the ductility coefficient reduces by12.0%, which leads toa seriously damage on the column button, and is not conducive to frame deformation. Theangle bolts margins reduces from85mm to70mm, the ultimate bearing capacity improves about7.0%, the ductility coefficient improves by21.1%, the node rigidity and thedegradation of bearing capacity has been improved. Therefore, this frame should be restrictthe column axial compression ratio appropriately and be minimized the angle bolts marginswithin the required range in order to increase the joint stiffness, and improve the frameductility.Another, three frame models were built by using ABAQUS finite element software inthe test, The results of the simulation and the test were compared based on the analysis. thegap between the two results is range from2.8%to16.2%. On this basis, a composite frameof three-layer one-span was designed, forcing loads in the situation of frequently occurredearthquake and rarely occurred earthquake with quivalent base shear method. Ultimatelythe storey drifts of this frame meet the requirement of the seismic code.