Do I understand you correctly that you want to model a composite beam only with QUAD elements?
If so, you need to connect the top flange with the concrete deck.
This can be done with spring elements and/or with couplings.
If you use the same structural line in both constructional elements (deck and flange), you get a rigid connection.
Why don’t you use a combination of SLNs and SARs? You could model the concrete deck with QUAD-elements and the steal beams with beam elements.
For this case we have a new detailed tutorial on our website.
www.sofistik.com > Infocenter - Overview > Documentation - Tutorials 2022 > bridge design > composite bridge
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