A Technique for Optimizing the Sequences Yielding under Load of Concentrically-Braced Steel Frames

Abstract

Concentrically-braced steel framing is widely used in tall buildings. Designing with adequate but not excessive seismic resistance is a challenge because of the limited experience of seismic failure and the huge variety of components used. A quantitative method for defining an acceptable range of component parameters is proposed and tested using published experimental data and finite element modeling. The method involves the structural yield mechanism control method of the steel concentrically-braced frame. It is proposed by inequality iteration of different structural components’ bearing capacities. It generates acceptable ranges for the parameters defining the properties of the columns, beams, and braces. The test results show that concentrically-braced steel frames designed within the recommended ranges will have the desired sequence of component yielding. The sequence is, however, highly sensitive to components’ parameter values. In practical engineering stochastic variability in the parameters must be considered.

Keywords

• concentric bracing
• steel frames
• yield mechanism control
• component parameters
• finite element analysis