D5.D.10.5 Clause 220.127.116.11(2) – Modification factor, f, for LTB checks
The Belgian NA specifies that the modification factor is to be obtained as per the default method given in EC-3. Hence the proposed implementation will use the existing functionality to work out the correction factor "kc" to be used in the modification factor f.
The program uses a default value of 1.0 for "kc". However, you can also input a custom value of "kc" by setting the design parameter KC to the desired value. You can also get the program to calculate the value of "kc" automatically by setting the value of the KC parameter in the design input to 0. This will cause the program to work out "kc" from table 6.6 of NBN EN 1993-1-1:2018. This will correspond to the end conditions and the bending moment of the member (i.e., the value of CMM parameter specified).
- For CMM = 7 the program will choose the value of "kc" to be either 0.90 or 0.91 based on the end moment ratio.
- For CMM = 8 the program will choose the value of "kc" to be either 0.77 or 0.82 based on the end moment ratio.
An additional check will also be performed as given below: