主筋の等価重心間距離による鉄筋コンクリート柱の曲げ終局耐力算定式の改良と中立軸位置および圧縮縁ひずみ度計算式の提案

抄録

Expressins, which can evaluate the ultimate bending strength about principal and diagonal axes continuously all range of axial load, were already proposed (see reference 2). One of the problems of these expressions, that was the method to express the effect of reinforcing bars arrangement, is cleared using equivalent distance between centers of reinforcement gravity, tention and compression group each other (Eq.(1)〜Eq.(3)). About ductility of flexure members, location of neutral axis and strain of extreme compression fiber are generally considered, and this paper propose expressions for calculating the former, formed by the ratio of compression area (Eq.(18)〜Eq.(20b)) and expression for calculating the latter (Eq.(24a)〜Eq.(25b), see Fig.7(a), 7(b)), using the relation of blanced axial load (Eq.(21)〜Eq.(23b)), see Fig.6), about principal and diagonal axes respectively.