In this tutorial, the fire condition on a reinforced concrete (RC) beam in Abaqus Thermal Analysis is studied. The concrete beam is modeled as a three-dimensional solid part. The steel reinforcement bars are also modeled as three-dimensional solid parts. This approach is necessary because wire parts and truss elements cannot capture heat transfer during the analysis.
To represent concrete behavior under fire, temperature-dependent material properties are used. Specifically, the specific heat and thermal conductivity of concrete vary with temperature. The same properties are defined for the steel bars.
A heat transfer step with a two-hour fire duration is applied. Three heat transfer mechanisms are considered:
- Convection (film condition): Fire temperature is applied using an amplitude curve.
- Radiation: Applied to the exposed surfaces of the concrete beam.
- Conduction: Considered between the steel bars and the surrounding concrete.
Boundary conditions are defined by fixing both ends of the beam. An initial temperature is assigned to the entire model. A fine mesh is used to ensure accurate results.
After the simulation, results such as nodal temperature, element temperature, temperature rise in the concrete beam, and temperature distribution in the steel bars are available. Figures of the results can be viewed for better understanding.
