[ANALYSIS]     How does the software consider beam property changes with pre-stressing tendon?

The option for beam property variation can be found in Analysis
Construction Stage Analysis Control Data  Beam Section Property
Changes.



If Change with tendon option is checked, the software considers section property as detailed below:


- For unbonded tendons : The duct area is deducted from the concrete gross area reducing the section property.
- For bonded tendons : The pre-stressing steel property is converted into an equivalent concrete property
as per the modular ratio and added with the concrete cross-section property as shown below.






With Just beam property,
Stress at top fibre generated by Prestress = P/Ac + P.e1/(I/Y1)

With modified beam property,
Stress at top fibre generated by Prestress = P/(Ac – Ast + m.Ast) + P.e2/(I-modified/Y2)