Effects of the Gravity-Load-Carrying System on the Performance of Planar Steel Concentrically Braced Frames

This paper investigates influence of the gravity-load-carrying system (GLCS) on the performance of braced frames. Analytical models ranging from low- to mid-rise buildings have been designed to use in this study. Two steel buildings with three and six story were analyzed with and without the GLCS to quantify their pushover response. Aspects of the GLCS that were investigated include the contribution of stiffness of beam-to-columns connections and the accurate P- effects especially in comparison to leaning columns. Moreover, this research investigates the potential for the development of inelastic deformations in the columns of the GLCS and the effect of such deformations on the performance of the structure based on ASCE 41. Results show the inelastic behavior in the GLCS has a less important effect. Furthermore the story mechanism which is the important and well-known failure mode in braced frames dominates the mechanical behavior of the structure and precedes any considerable difference which could be achieved triggered by the GLCS.

Keywords:

Braced frames , Gravity framing , P- effects , Partially-restrained connections , Pushover analysis