Title: Analytical Study of Torsional Moment Induced by Shifting of Shear Center of RC Cross Sections

Author(s): H. Nakamura, Y. Yamamoto, A. Itoh, and T. Tanabe

Publication: Special Publication

Volume: 237

Issue:

Appears on pages(s): 177-188

Keywords: asymmetric-resistant mechanism; biaxial loading; fiber technique; induced torsional moment; shear center; shear flow

Date: 8/1/2006

Abstract:
For members with symmetric cross-sections, the geometric centroid and shear center are coincident. Thus, if lateral load is applied through the geometric centroid, a torsional moment is not induced. However, a RC cross sections typically develop an asymmetric resistance mechanisms, resulting in progressive movement of the shear center away from the geometric centroid as nonlinearity increases and the section responds to bi-axial loading. In this study, the mechanism causing shifting of the shear center for RC cross sections was investigated using frame elements with a fiber-type discretization of the member cross-section. Then, the effects of the torsional moment induced by the shifting of the shear center were discussed, and it was shown that the effect in not negligible in practical design.