H-section braces are widely used for seismic-proof elements in various kinds of structures. However, when they receive the cyclic loading beyond the expected seismic loads, they cause not only overall-buckling, but local buckling. It is known that such local buckling cause stress concentration within limited zones, and easily lead to the fracture of the member itself. Various hysteretic loop models for such braces have been proposed and used for timehistory analysis, however, it is not easy to predict the point of the fracture, their cumulative deformation capacity and energy dissipation capacity until the fracture. In this paper, cyclic loading tests on various H-section braces are carried out, and their fracture mechanism, relationship between the slenderness ratios and width-thickness ratios are researched. Their strain concentration mechanism is discussed through various analyses, followed by proposing easy evaluation method of their cumulative deformation capacity.
