Method of analysis second order effect

 

There are three possibilities for calculation second order effect in SEN and method for analysis can be set via property Method of analysis second order effect

• No - second order effect is not taken into account
• Simplified - second order effect is calculated by using simplified method (method based on nominal curvature or method based on nominal stiffness). Type of simplified method can be set via Type of method subgroup Simplified method, see chapter "Type of simplified method"
• Auto(general) - type of method for calculation is selected automatically depending on type of combination and selected functionality. The simplified method is used for :
  • linear combination
  • nonlinear combination without bow and global imperfection and functionality Geometrical non-linearity and RC material non-linearity are OFF in project setting.

  For other case the general method (method based on material and geometrical nonlinearity is used), see module PNL, chapter "Introduction"

The default value of geometrical imperfection (bow imperfection) for general method are defined in Concrete setting, see "Bow imperfection"

If general method is used for calculation second order effect (PNL calculation) and simplified method is defined for analysis second order effect in concrete setting or concrete data, then second order effect is taken into account twice(by PNL analysis - general method and by simplified method). In thi case it is necessary to change method of analysis to NO or Auto.