Mehrdad Memari

Response of Steel Reduced Beam Section Connections Exposed to Fire

AbstractSteel structures may be vulnerable to fires; therefore, work is underway in several quarters to advance performance-based engineering (PBE) of steel frames for fire conditions. Both experimentation and finite-element simulations are necessary tools in PBE for assessing the behavior of structures under elevated temperatures. Numerical modeling of the overall structural system using line-element models fails to capture the localized behavior of connections due to the simplistic nature of such models. With advances in computation, attention is shifting to three-dimensional (3D) models, which are better able to capture the behavior of connections. Accurate predictions of structural response require the inclusion of realistic boundary conditions such that the interaction between the connections and the surrounding structure is properly captured. The study reported herein evaluates the response of steel frames with reduced beam section (RBS) connections under a typical compartment fire, with temperature...

Effects of Fire Following Earthquakes on Steel Frames with Reduced Beam Sections

The occurrence of fires following an earthquake in steel structures is a significant issue in areas of moderate-to-high seismicity. The current seismic design philosophy permits a certain degree of damage during earthquakes, making the structures more vulnerable when exposed to the additional demand of fire loading. Evidence from previous earthquakes has shown high variability in the damage sustained by active and passive fire resistance systems and structural loss due to fires following earthquakes has been observed. This paper provides insight into the effects of the local behavior of reduced beam section (RBS) connections during fire following earthquakes on the global response of steel moment resisting frames. This is achieved through investigating the response of a 9-story steel frame designed for the Los Angeles region using nonlinear finite element analyses. The models are developed and analyzed under representative loading scenarios and the results are presented and their implications discussed.

Stability of Steel Columns Subjected to Earthquake and Fire Loads

AbstractAssessing the stability of steel building frames exposed to fire conditions is challenging because of the need to consider the elevated temperature properties of steel, nonuniform heating o...