The features for modeling, calculation, and result evaluation related to structural analysis are described in detail in the RFEM 6 and RSTAB 9 manuals.
This section provides notes on the input that is important for the analysis of concrete and concrete design.
Linear Analysis
The design of reinforced concrete structures is usually based on linear structural analyses. For the reinforcement determination, including the serviceability limit state design, the internal forces are determined linearly; then the cross-section check is performed.
- This means that the structural analysis can be performed with linear elastic materials.
- The reinforcement and the crack formation typical for reinforced concrete with the corresponding nonlinear reinforced concrete material models are considered at the cross-section level during the concrete design.
Nonlinear Analysis
In nonlinear analysis, the nonlinear behavior of reinforced concrete, including crack formation, is already taken into account during the determination of internal forces. This results in realistic stress states and, consequently, internal force distributions that differ significantly from the linearly determined internal forces in statically indeterminate structural systems due to stiffness redistributions. For the serviceability design, for example, this means that the nonlinear material behavior of concrete is necessary to take into account for a realistic calculation of deformations, stresses, and crack widths.