Experimental Study And Nonlinear Finite Element Analysis On The Special-Shaped Column Joints Of Reinforced Concrete Frame Structures

Because the thickness of beam is equal to wing and belly board of columns, and the ratio of highness and thickness of the special-shaped column section is large and steels are dense in the joints of beam and column, concrete is hardly flapped and so the special-shaped column joints are weaker than the rectangle joints.Based on the experimentation of 6 frame joints with T-shaped cross section column under cyclic loads, the paper researches the anti-seismic behavior of the joints applying in practice. The following problems have been analyzed: failure form of joints,hysteretic behavior, the anchorage of beam bars and the influence factors of the strengths of anti-shear and so on. The joints of T-1, T-2 and T-3 are the first group, T-2 and T-4 are the second group, T-2, T-5 and T-6 are the third group. According to the different aims, the papers research the anti-shear performance reflections of the beam section height h, the axis-pressed ratio and the hoop steel ratio.The paper deeply analyzes the destruct form and crack shape. The joints' crack shape appears reverse "K" but not the rectangle joints' "X" shape. Finally, the paper points out that the endure mechanism is liable to the inclined press-pole mechanism.The researches of nonlinear finite element and experiment indicate that the effect of anti-shear which is aroused by the width of the joints' wing board. Finally, thepaper points out that the modified parameter ζ_f which reflect anti-shear is relatedwith the ratio of anti-bending stiffness of beam and column, but not just according to the difference of b_f and b_c.Finally, this paper researches the nonlinear finite element analysis with the universal programmer-ANSYS and validates the failure form of joints and the influence factors of the strengths of anti-shear once more.