Fe Simulation of Space Steel Frames in Fire With Warping Effect

Abstract

Most structural fire resistance analyses are confined to 2-D frames. To gain a more in-depth understanding of the response of a steel frame at elevated temperatures, 3-D simulations are necessary. This paper outlines the formulation of a two-noded 3-D beam-column to study the response of a steel frame in fire. The program is capable of small-strain large deformation analysis. Warping effect, a significant phenomenon in thin-walled members, is considered in the formulation. Degradation of steel mechanical properties at elevated temperatures is also considered, while thermal gradient is considered by slicing a cross-section into discrete segments. Creep can be either implicitly or explicitly taken into account. Several widely-used beam-to-column connections are approximated as zero-length semi-rigid springs. Their nonlinear moment-rotation relationships at elevated temperature are incorporated into the program. Unloading of both material stress-strain curve and moment-rotation characteristics of a connection are accounted for. The Newton-Raphson method is employed for nonlinear solving procedure. At the latter part of this paper, the program is verified against benchmark tests. All of them demonstrate the accuracy and reliability of the program.

Axial restraint effects on the fire resistance of composite columns encasing I-section steel

“…Program FEMFAN-3D was extended from a program developed for skeletal 3-D steel frame analysis [26]. In FEMFAN-3D, the bounding among concrete, rebar and steel surfaces is assumed to be perfect: there is no slipping and no cracking.…”

Second-Order Analysis of Steel Sheet Piles by Pile Element Considering Nonlinear Soil-Structure Interactions

“…For eliminating the error accumulating in the nonlinear calculation, a new incremental-iterative procedure is proposed based on Newton-Raphson procedure [30] to integrated UL method and element formulation. And the flowchart is plotted in Fig.…”

Fire resistance of composite columns with embedded I-section steel — Effects of section size and load level

“…In the first part of study, four groups of composite columns with embedded I-section steel are analysed by a FE program named FEMFAN-3D [17] for examining effects of column size and load level. All columns are 3 m long and consist of square cross-section with embedded I-sections (Fig.…”

“…FEMFAN-3D is a small-strain-largedeformation program extended from skeletal 3-D steel frame analysis [17]. Bonding among concrete, rebar and steel surface is assumed to be perfect; that is, neither slippage nor cracking occurs.…”