CSI Software uses a moment-area technique to calculate deflection during composite design. For common cases in which beams exhibit composite behavior, this method is effective.
However, when beams deflect upward under conditions of double- or triple-curvature (with tension along the top fiber), behavior may not be composite. In such cases, use either of the following methods:
- Steel-frame beam design post-processor.
- Check such members manually.
In ETABS, Context Help provides additional information on this topic, available through Help > Documentation > Composite Beam Design.