RESEARCH ON THE INFLUENCE OF THE FINITE ELEMENT MESH ON THE TEMPERATURE DISTRIBUTION OVER THE RIBBED PLATE IN FIRE MODELING

Abstract

The article investigates the influence of finite element mesh type on the
temperature distribution in reinforced concrete ribbed slabs during fire modeling. The
thermal task was solved using three mesh generation methods: Automatic, MultiZone,
and Body Sizing. The results revealed significant differences in the accuracy of
temperature modeling depending on the mesh type. The Body Sizing method
demonstrated the most physically accurate temperature distribution in concrete and
reinforcement, closely aligning with the standard fire temperature regime. Unlike the
other methods, it avoided non-physical negative temperature values in the
reinforcement, which were observed with Automatic and MultiZone meshes.

Key findings indicate that mesh optimization is critical for improving the
reliability of thermal modeling results. A correct temperature distribution model
ensures a more accurate representation of material properties, particularly their
mechanical behavior under fire conditions. For instance, the maximum concrete
temperature observed with the Body Sizing method was 944.26 °C, which is consistent
with the standard temperature regime, compared to 967.96 °C and 956.15 °C for the
Automatic and MultiZone methods, respectively. Similarly, reinforcement temperatures
followed the same trend: 887.49 °C for Body Sizing versus 936.52 °C for Automatic and
897.44 °C for MultiZone.
The study emphasizes the importance of selecting an optimal finite element
model to evaluate fire resistance accurately. This research contributes to improving fire
safety assessments by enabling more precise predictions of the thermal behavior of
reinforced concrete structures. Such findings are essential for designing safe and
efficient structural systems, ensuring compliance with fire resistance standards, and
enhancing the performance of building components under fire exposure.
The results are valuable for professionals involved in structural design and fire
safety engineering, offering a foundation for developing advanced modeling techniques
to predict and improve the fire resistance of ribbed slabs and similar constructions.