Abstract
Authors suggested the method to attach flat bar on the neutral axis as one method to improve plastic deformation capacity of the beam in the past study. This paper describes that plastic deformation capacity of the extremely shorter beams is improved by this suggested method, and shows the reason why plastic deformation capacity of beam is improved by attaching with flat bar. The web shear buckling strength is clarified by the difference of the attached shapes of flat bar on the neutral axis, by considering Saint Venant torsion. The optimum shape of flat bar which attach on the neutral axis of beams is investigated by finite element method. To verify the optimum shape of flat bar, the test of the beam with neutral axis reinforcement is carried out. The effect of the reinforcement steel plate on the plastic deformation capacity of the beam is clarified by analytical and experimental approach.
