Querschnittsberechnung von Stahlbetonstäben

Cross-Sectional Analysis of Reinforced Concrete Beams - A Hybrid Approach

Many reinforced concrete structures can be analysed using beam elements. The simplicity of the application of beam elements contrasts the complexity of the mechanical and mathematical formulation. The whole information of the beam continuum has to be projected on an one-dimensional element. Especially regarding a non-linear analysis this is a big challenge. The geometrical nonlinearity is regarded as solved. Considering material nonlinearity, however, no established, generally accepted model for spatial reinforced concrete beam elements exists so far. Within beam theory, the material nonlinearity is captured on cross-sectional level. In a cross-sectional analysis, the stress and strain state corresponding to sectional forces is determined. The hybrid approach is based on dividing the cross section in areas with uniaxial and biaxial stress and strain states. The biaxial area is modelled by membrane elements and contributes to all six sectional forces. The uniaxial area is restricted to normal force and bending moments.