材端回転拘束を受ける鉄骨筋違の繰返し弾塑性性状に関する研究

Abstract

Cyclic behavior of a steel brace elastically restrained at both ends was studied experimentally. The specimens were manufactured by shaping SS 41 mild steel sheet. Ratio of member length l to radius gyration of the cross section i, stiffness of rotational restraining spring at both ends, eccentricity of a load and shape of the cross section were varied in this test. The results may be summarized as follows, 1) Value of l/i and existence of restraining springs influence on the cyclic axial load-displacement curves remarkably. 2) Under the identical value of l/i, the plastic energy absorption capacity of a restrained brace is considerably larger than one of a pin supported brace. 3) Also under the identical value of l_k/i, the ratio of the effective buckling length l_k depending on the end restraints to i, the plastic energy absorption capacity of a restrained brace is larger than one of a pin supported brace. 4) As the stiffness of restraining spring increases the value of magnification factors α that explain the effects of end restraints on the cyclic behavior of braces under the identical value of l_k/i decreased. 5) Eccentricity of a load does not hardly influence on the cyclic behavior of a brace, expect for the difference in the maximum compression load attained in the initiate loading.