Prestress

The prestress has to be assigned to the post-tension tendon as a member load.

1. banner.text@Currently, prestress can only be described as longitudinal strain. A new load type is under development.

Defining Prestress as Axial Strain

You can assign the prestress to a tendon as a load as usual:

1. Open the New Member Load dialog box.
2. In the Load Case section, set the load case of the action category “P – Prestress” (see the chapter Prestress Load Cases).
3. In the “Categories” section, select the “Longitudinal strain” load type.
4. Specify the load size of the strain ε. Since the prestress is to be effective as a shortening of the tendon, use a negative sign.
5. Assign the load to the tendon member.

The conversion of the tension force into an equivalent strain is currently still necessary to be done manually. One way to do this is to use parameterized input.

Determining Prestress Action as Axial Strain ε

The prestress losses also need to be determined manually. Automatic consideration of the losses for post-tensioned composite action in the form of a special member load is currently under development.