Introduction

The internal forces, which are used for design and checks of concrete members can be different as internal forces calculated from FEM analysis. The differences may be caused by:

• for compression member (column)
  • taken into account eccentricities caused by imperfections, see "First order bending moments with imperfection"
  • taken into account second order eccentricity, see "Calculation of second order effects"

• for beams and beams as slab

  • taken into account additional tensile forces caused by shear and torsion (shifting of bending moments), see "Additional tensile forces caused by shear and torsion (shifting of bending moments)"
  • reduction of bending moment and shear force above/near support "Reduction of shear forces and bending moment"

Except of these differences, the user has possibility to modify (switch ON/OFF some components or set some limit of each component of internal forces) internal forces for each type of member, see "Modification of internal forces"

The following preconditions are used for calculation :

• The shifting of bending moments is taken into account only for beams and beams as slab and in both directions
• The second order effect and geometrical imperfection are calculated only for column in compression
• Cross-section with one polygon and one material is taken into account for calculation second order effect and imperfection in version SCIA Engineer 15
• The material of all reinforcement bars have to be same in SCIA Engineer 15