A hysteresis restoring force characteristic model and a method for calculating the equivalent viscous damping ratio of a beam with two rotational springs at both the outer end of the general and widened beam end were proposed. A damage evaluation method applying the member model was proposed, and the reduction in rigidity according to the degree of damage was reflected in the hysteresis restoring force characteristic model of reused members. The dismantled specimens were assembled again and retested to confirm the consistency between the model and the results.