Effective flange width composite bridge


I have create a composite bridge (steel+concrete). I have followed the tutorial from 2022 on your website.

This tutorial do not talk about effective flange width, see EN 1994-1-1 or EN 1994-2.

I found a old question about this and it says that it need to be set manually for the T-beams cross-section, according to EN 1994.

Is this still relevant in Sofistik FEA 2022? If I change the cross-section in support areas I don’t get enough self-weight from concrete (and formwork?) if I follow the tutorial. I think that the formwork will be to low also in the support areas.

How do I get the linear transition for the effective flange width between span areas and support areas illustrated in EN 1994?

Best regards Andreas

Hello Andreas

The effective flange width can be considered with a NEFF (non-effective area). This function was not considered in the tutorial because the span between the columns is quite large and the non-effective width is therefore negligibly small. For this reason, we didn’t want to overcomplicate the example.

The following tutorial explains the definition of a non-effective area.

You could also look at the TEDDY example below.

TEDDY > File > Examples > aqb > english > aqb1_6_composit_neff.dat

Best regards
Frederik Höller
Your SOFiSTiK Support Team