Fire response of a 3D multi-storey building with buckling restrained braces

Abstract

This paper investigates the performance of a three-dimensional multi-storey structure with Buckling Restrained Brace system (BRBs) under fire condition, using a sequentially coupled nonlinear thermal stress analysis. Efficiency of using BRBs in enhancing the strength and stiffness of a structural frame is compared with that of Ordinary Concentrically Bracing system (OCBs) under various fire scenarios. The proposed numerical model is verified by a series of full-scale fire tests carried out on an 8-storey structure at Cardington. The results indicate that the vertical movement of heated (buckled) column in the structural frame with BRBs is lesser than that with OCBs. Consequently, the tensile force and bending moment of the beam adjacent to the buckled column in the former is lesser than the latter. Also, BRB elements can perform better in redistributing the load sustained by heated columns without any buckling occurrence in the bracing member, in comparisons to the ordinary system. In general, it is observed that BRBs manifest an improved performance in re-stabilization of structural frame against fire for a longer period of heating time, such that a better fire resistance is offered to the whole building as compared to OCBs, due to a higher restraint provided onto the structure.

Thermally-induced responses of triaxially woven fabric composites

“…The model is exposed to a temperature increase of 100 °C. 8-node linear brick elements with incompatible modes (C3D8I elements) are employed as it has been noticed that the incompatible states formulated for this element exhibit better flexural response, thus requiring lesser mesh to reach convergence versus a normal mode linear solid element [ [23] , [24] , [25] , [26] ]. There are 64 elements in every flat rhombus and sloping region.…”

Numerical‐experimental analysis of a braced steel frame subjected to fire following earthquake

“…The loss of fire protection is particularly dangerous for steel structures because the high thermal conductivity associated with small profile thicknesses entails quick temperature rise in the profiles with consequent fast loss of strength and stiffness. Most of the literature involve numerical simulations on steel moment resisting frames [1][2][3] [4] and only a few of them are dedicated to buckling-restrained and conventional brace systems [5] [6]. Both developed a framework for evaluating the post-earthquake performance of steel structures in a multi-hazard context that incorporates tools that are capable of probabilistic structural analyses under fire and seismic loads.…”