The present authors had proposed the K-braced frame with shear resistance member made of ordinary steel as a hysteretic damper. In this paper, for convenience of seismic design of the braced frame with the damper, the strength evaluation expression for the shear resistance member is proposed. This expression is based on limit analysis theorem for continuous media using the assumed rigid-plastic deformation fields. Also, elasto-plastic finite element analyses are performed on various kinds of shear resistance member under monotonic and cyclic loading in order to investigate the optimum shape of shear resistance member, in which the equivalent plastic strain is adopted as the index of damage concentration. These results show that 1) the present strength evaluation expression has good accuracy and validity compared with finite element analyses results. 2) the optimum shape of shear resistance member, which minimize the equivalent plastic strain, are clarified.
