EN 1992-1-1:2003 and EN 1992-1-1:2003 #5.8.5 define non-linear second order analysis as general. This analysis method can be performed with MatrixFrame®.
If linear analysis is performed code allowing using one of two simplified methods:
- method based on nominal stiffness
- method based on nominal curvature
In MatrixFrame® method based on nominal curvature, which is described in chapter #5.8.8, is implemented. Design moment MEd consist from two parts:
M0Ed – first order moment with included effect of imperfections calculated according chapter #5.2(7);
M2 – is nominal second order moment calculated according #5.8.8.2(3).
If in column element is acting different moments first order moment must be recalculated according equation (5.32).
Final value of design bending moment will be obtained like maximum from modified first order moments from end moments and intermediate moment like it is illustrated in picture below:
