ABSTRACT
Numerical analyses of RC Beam structures in case of fire need the application of finite element models considering material and geometrical nonlinearities. Such a numerical model is implemented in the program FS3D (Mihajlov 2009). This program is based on a 3D non-linear beam finite element. Its cross section is defined in segments (fibers), where each segment can obtain different materials, temperatures and mechanical properties (Figure 1). So-called “void” fibers allow the modeling of arbitrary cross section shapes. Thermal expansion, cracking or crushing of concrete and changing of material properties of reinforcing steel are implemented according to Eurocode regulations.
