Modeling Composite sections as beams

Please refer to the section 1.7.7 of the Technical Reference Manual titled Composite Beams and Composite Decks. For your case the Explicit Definition Method ( first method ) would be appropriate.

In the GUI, the option is available when you click on the Section Database button from within the Properties - Whole Structure dialog box. You can then choose the appropriate steel section and define the composite properties as marked in the picture below

Please refer to the section 1.7.7 of the Technical Reference Manual titled Composite Beams and Composite Decks. For your case the Explicit Definition Method ( first method ) would be appropriate.

In the GUI, the option is available when you click on the Section Database button from within the Properties - Whole Structure dialog box. You can then choose the appropriate steel section and define the composite properties as marked in the picture below