| Abstrakt: |
The 2005 AlSC Specification for Structural Steel Buildings includes a stiffness reduction factor, τb, in Appendix 7 to be used in the direct analysis method to account for the presence of residual stresses and their influence on the second-order effects of frame behavior. The 2005 Commentary includes a stiffness reduction factor, τb, to be used along with the effective length nomograph to account for the influence of column inelasticity due to residual stresses on effective length. These two stiffness reduction factors are intended to account tor the same effect yet they are different. This paper provides the background for these two factors, and it will demonstrate that τb is the more correct stiffness reduction factor. The 2010 AlSC Specification will recommend its use with both the direct analysis method and the effective length nomograph. [ABSTRACT FROM AUTHOR] |
