FAQ 002108 EN-US

Calculation RFEM RSTAB 5.xx 8.xx

When calculating a result combination, I receive the "Warning No. 30014 – Incorrect addition of load cases in the result combination! The result combination contains load cases or load combinations with results containing second‑order effects, which points towards nonlinear relationships and therefore cannot be added together..." What does this warning mean?


This warning appears in the case of the following result combination definitions:

  • LC/CO + LC/CO
  • Factor* LC/CO or factor* LC/CO

For example, two LCs are superimposed with factors and the 'or' criterion in the second case. Since the LCs are calculated according to the second-order analysis, the results have a nonlinear relation – for example, a duplication of the axial force is not necessarily accompanied by a duplication of the moment.

If you provide the results of the load combination with a factor, each internal force is multiplied by it. Therefore, it is assumed that the results have a linear relation. This contradiction (nonlinear calculation of the results with linear multiplication) causes the message described above.


load case, load combination, result combination, warning, incorrect addition, second-order analysis, superposition

Contact us

Contact Dlubal Software

Did you find your question?
If not, contact us via our free e-mail, chat, or forum support, or send us your question via the online form.

(267) 702-2815


RFEM Main Program
RFEM 5.xx

Main Program

Structural engineering software for finite element analysis (FEA) of planar and spatial structural systems consisting of plates, walls, shells, members (beams), solids and contact elements

Price of First License
3,540.00 USD
RSTAB Main Program
RSTAB 8.xx

Main Program

The structural engineering software for design of frame, beam and truss structures, performing linear and nonlinear calculations of internal forces, deformations, and support reactions

Price of First License
2,550.00 USD