コンクリート充填角形鋼管柱の復元力特性モデル

Restoring force characteristic model for bending moment–rotation angle relationship of concrete‐filled square steel tube beam‐columns

“…Next, regarding estimation formulas for the ratios of the rotation angles at the 95%, 85%, and 80% strength reduction points to the 90% reduction rotation angle, the buckling length–section depth ratio was selected as a factor, similar to Ref. [6]. The rotation angle ratios for cyclic loading ( i r 90 = R i / R 90 ) and monotonic loading ( i r ′ 90 = R ′ i / R ′ 90 ) were thus obtained from Equations (19) and (20) below, respectively.…”

“…The strength and deformation in the model are estimated from a bending moment‐curvature ( M ‐ ϕ ) relational model that the author proposed 5 for the elastoplastic regions at the beam‐column ends. Because it is complicated to calculate the deformation of each characteristic point from the M ‐ ϕ relational model, a simple empirical expression was devised from the experimental data, and it also included proposed hysteresis loop 6 . The restoring force characteristics of the shearing force–deformation relationship, in which the shearing force is reduced by an additional moment due to the axial force (the P −Δ moment), have been shown experimentally to assess the structural performance of CFT beam‐column.…”

“…Because it is complicated to calculate the deformation of each characteristic point from the M-ϕ relational model, a simple empirical expression was devised from the experimental data, and it also included proposed hysteresis loop. 6 The restoring force characteristics of the shearing forcedeformation relationship, in which the shearing force is reduced by an additional moment due to the axial force (the P−Δ moment), have been shown experimentally to assess the structural performance of CFT beam-column. However, in the standard frame analysis software used in the structural design, when the P−Δ moment of beam-columns is considered, the P−Δ moment is calculated in the software and the moment is added to beam-column's moment.…”