Structural analysis technique of simple steel structures exposed in fire using ABAQUS

Abstract

Fire safety in building design is a significant concern nowadays to ensure people's safety and decrease construction cost. For a structural analyst, understanding the structural fire behaviour is very important in building design phase. To do so, numerical analysis techniques such as the finite element method are used to solve the structure’s response when structures are exposed to the fire. This thesis work aimed to develop a thermal and structural analysis technique to simulate the fire test using Abaqus finite element software. Its main objectives are developing relevant analysis techniques and procedures to replicate the fire test virtually and validating and benchmarking the developed technique for three fire tests. HAMK Tech Research Unit, Finland commissioned this thesis work. At first, temperature-dependent thermal and mechanical properties of construction material included steel and concrete were collected. Then, thermal and structural analysis procedure is developed. Finally, structural analysis of simple steel structure exposed in the fire was simulated, and the response between Abaqus and fire test results were compared.

The overall conclusion from this thesis work was that Abaqus could predict the structural response of simple steel structure exposed in the fire with good agreement compared to measured results using beam and shell element model. It was observed that defining nonuniform temperature distribution in the beam section temperature point is difficult because only one temperature versus time curve can be defined. Similarly, it was observed that Abaqus could perform highly nonlinear structural analysis using Abaqus/Explicit dynamics procedure for structures exposed in the fire without convergence issue. Lastly, this thesis project work could be used as a guideline to perform structural fire analysis using Abaqus for simple steel structure exposed to fire.