Finite-Element Analysis of Isolated and Integrated Structural Steel Members Exposed to Fire

Abstract

Ambiguities in current fire design codes have triggered conflicting responses from researchers and professionals about steel buildings in fire. This is because fire codes do not consider the integrated structure of the building, but are based on the tests and models of the individual structural members of a construction subjected to a standard fire (ISO 834 or ASTM E 119). This study designed a four-story steel frame structure containing five bays with a bay span of 12 m and a height of 3.5 m according to Eurocode 3, considering all joints as being simply supported. Four different fire scenarios were modeled with reference to members of the assembled structure utilizing the Vulcan software package considering standard and parametric fire curves on exposed and protected sections. The results were compared with those obtained by exposing to the same fire curves an isolated beam member equal to those belonging to the frame under investigation. The comparison shows that the assembled members in the modeled structure had a better fire performance than did the isolated members. Because connections are important components of structures, we believe that the effects of connections on the fire performance of structures should be studied in the future.