Study On Seismic Behavior Of Beam-column Joint With Beam-end Steel Fiber Concrete Plastic Hinge

Steel fiber reinforced concrete is a new type of building material and is widely used in the field of civil engineering, both in China and abroad, owing to its excellent performances in tension, shear, crack resistance, shockproof, fatigue resistance, high tenacity. It is naturally a hotspot for the application of steel fiber reinforced concrete in the seismic structure and the problem is how to use steel fiber partially to improve the seismic performance of beam-column joint of frame structure. Most studies at present are focused on mixing the steel fiber into the concrete of core part of joint. From another point of view, in this paper, steel fiber was mixed into the concrete of beam-end part of joint to improve the capacity of energy dissipation of plastic hinge and the ductility of the structure. The contents of the dissertation can be divided into the following two parts.(1) By comparable experimental study of one common joint and the other two joints with beam-end steel fiber concrete plastic hinge under cyclic load, the seismic behavior such as the failure pattern, hysteresis characteristic, skeleton curve, ductility, capacity of energy dissipation were compared synthetically and the influence and improvement on earthquake-resisting performance of beam-end steel fiber concrete plastic hinge were analyzed.(2) Using finite element software—ANSYS, three different models were set up, loaded on and analyzed. By comparing the theoretical and experimental results, synthetical seismic performances of joint with beam-end steel fiber concrete plastic hinge were valued.The experimental and numerical results indicated that beam-end steel fiber reinforced concrete plastic hinge could increase the stiffness of the joint as well as delay the stiffness degradation after the joint was yielded, so that the ductility of the whole joint was improved. It was also found that beam-end steel fiber reinforcedconcrete plastic hinge did not have influence and improvement on limit of ultimate strength of the joints .