Product Overview:

This tutorial focuses on simulating a steel beam subjected to both fire and mechanical loads using Abaqus. The steel beam is modeled as a three-dimensional solid, although it can also be represented as a shell part.

The methodologies for evaluating the fire resistance of steel structures are well-documented in existing literature, primarily emphasizing analytical approaches. To accurately represent the thermal behavior of the steel beam during fire exposure in the initial analysis, specific thermal properties—such as temperature-dependent specific heat, conductivity, and density—are utilized. For the mechanical analysis, temperature-dependent parameters including density, elasticity, and plasticity are incorporated. During the fire analysis, a heat transfer step featuring a prolonged timestep is applied to simulate the fire scenario. The fire scenario is treated as a film surface condition, and to model the fire’s impact as a function of time and temperature, a tabular amplitude function is employed. Additionally, radiative heat transfer is modeled for the underside of the steel beam.

The nodal temperatures obtained from the initial analysis are then introduced as initial conditions for the mechanical analysis, influencing the stress and strain experienced by the beam. In the mechanical simulation, a static general step is chosen, and mechanical pressure is exerted on the beam’s upper surface. The elevated temperatures lead to plastic deformation within the beam.

After completing the simulation, various outputs, including stress, strain, displacement, and more, can be analyzed.