After performing several elasto-plastic shaking table tests of one-tenth scaled five-story frameworks on the "first-story energy-concentrated steel structure with flexible-stiff mixed frames" based on energy theory, the following matters were confirmed : Most of input energy due to a severe earthquake can be absorbed by stiff members in the first story. First-story flexible members and the second and higher stories can remain almost elastic. The residual displacement of the first story can be constrained very small. Compared with the test result, it is demonstrated that a response analysis result using elastic-perfectly plastic type as restoring-force characteristics without damping ran express the actual phenomenon with respect to energy absorption characteristics.
