The authors have proposed concept to realize beam yielding mechanism of a steel moment-resisting frame by applying a pin support system to midpoints of the first story columns. As a pin connection, an encapsulated-rubber rotational bearing is newly proposed. Seismic performance of the system is examined by a static cyclic loading test of a partial frame, consisting of the first story column and the second floor beams with an proposed rotational bearing. Test results showed a frame with a proposed rotation bearing had stable hysteresis behavior up to a story drift of 0.03 rad.
