Structural Performance of Circular Hollow Section Damper Under Loading in Circumferential Direction

Abstract

A circular hollow section steel damper exhibits equivalent structural performance in an external force direction owing to its circular cross-sectional shape. When a circular hollow section steel damper is placed in a building with stud supports, the stud supporting the damper is connected to the upper and lower beams. When an earthquake occurs, the shear force in the in-plane direction acts on the damper through the stud from the beam. However, depending on the three-dimensional behavior of the building and the arrangement of the damper and surrounding members, a load other than that in the in-plane direction might act on the damper. In this study, the mechanical characteristics of a circular hollow section steel damper in the external force direction were analyzed according to the cyclic load in the circumferential direction using finite element analysis. A reliable finite element analysis model was constructed based on the results of a previous study on unidirectional cyclic loading. The analysis results under cyclic loading conditions in circumferential directional cyclic loading were compared with those under unidirectional cyclic loading. The hysteresis curve resulted in a circular shape under circular directional loading. Moreover, the x- and y-direction load–displacement curves showed a similar strength-increasing ratio to unidirectional loading. Under circumferential directional loading, the strain was concentrated at the end of the welded part, similar to that under unidirectional loading. Furthermore, the strain was distributed in the circumferential directional loading, showing a smaller value than that of unidirectional loading.