Parameters of the post-tensioned internal tendon

Specifies the name of the tendon.

This item allows the user to add a short description, if required.

Defines the number of the tendon.

(informative value)

Shows the type of the tendon (internal / external).

Selects the layer of the tendon. Each layer can be assigned to a different layer, if necessary.

Selects the type of the geometry input.

Source geometry

For this type of geometry, the user must define the shape of the tendon geometry in advance. The predefined tendon is then allocated to the 1D member and, if necessary, modified in its shape to follow the shape of the 1D member. The tendon is not stretched to fit the length of the 1D member. But, it may be curved to follow the real shape of the 1D member. The latter may be used to simplify the input of tendons in curved 1D members. The tendon is defined by its "projection" into plane. Then, it is allocated to the curved 1D member. The shape of the tendon is modified, so that the local x-axis of the tendon follows precisely the local x-axis of the 1D member.

Direct input

For this type of geometry input, the user defines directly the shape of the tendon in the graphical screen where the 1D member to-be-reinforced is displayed. In order to define exactly the shape that is required, an additional toolbar is added to the top of the command line. This added toolbar allows for the input of circular and parabolic intervals.

Reference line with source geometry

This possibility is a kind of combination of the two previous options. For more information read a separate paragraph at the end of this chapter.

Note: The same toolbar is displayed when e.g. a new 1D member is input.

Specifies the way in which the local coordinate system of the tendon (y- and z- axis) is defined.

(This item is available only if the Geometry input is set to Source geometry)

Here, the user must select the required source geometry for the tendon. It is also possible to invoke the Tendon source geometry manager and input a new source geometry.

(This item is available only if the Geometry input is set to Source geometry)

It is necessary to define where the origin of the source geometry is to be put in the model. In other words, the user must position his/her tendon into the 3D space.

The position is defined by (i) the offset from the origin of the coordinate the local coordinate system of the allocated 1D member or (ii) in the global coordinates.

(This item is available only if the Geometry input is set to Source geometry)

These three values define the position of the tendon source geometry origin. The exact meaning depends on the adjustment made in the item above.

Specifies the material of the tendon.

Defines the number of wires or strands in tendon.

Specifies the number of identical tendons (e.g. in walls of single or multi box section, etc.) which create a group. For details see the picture below the table.

(informative value)

Shows the sectional area of the tendon.

Defines the diameter of the tendon duct. The parameter is used for the test of tendon geometry only.

This item opens an extra dialogue where the user can select which 1D members are allocated to the tendon. In general, more than one 1D member can be allocated to one tendon, as e.g. in the case of several shorter 1D members running one after another that are reinforced by one long tendon.

The user must select a load case from a list. The list contains only the load cases the Load type of which is set to Prestress.

The effects of the prestressing of the tendon will be stored in this load case.

The type of stressing is analogous to pre-tensioned tendons.

The program offers four options. Simultaneous anchoring of both ends is neither economic nor practically feasible.

The options offered in the list are self-explanatory.

Friction coefficient for curved part of tendon.

(only for CSN / STN standard)

Friction coefficient for the straight part of tendon.

(only for EC2, NEN)

The unintended angular displacement of the tendon.

Defines the anchorage set at the beginning of the tendon.

Defines the anchorage set at the end of the tendon.

Specifies the duration of keeping constant stress during the correction of relaxation.

Initial stress at the beginning of tendon (before seating).

Defines the part of the tendon at its beginning which is taken into account when calculating the losses, but not when creating the structural model. This is useful in the case that the 1D member (and tendon) protrudes beyond the theoretical support and the user does not want to include this part of the structure into the model, but wants to have proper losses and tendon geometry for the export into CAD.

Analogous to the previous item.

Defines sections where results are presented.

Circle + tangent

Circle: the parameter is the distance between the vertex and the tangent point, see picture below.

Circle + radius

Circle: the parameter is the radius of the circle, see picture below. The radius and two tangents determine the circle. The length of the tangents is calculated automatically.

Symmetrical parabola + tangent

Parabola: the parameter is the distance between the vertex and the tangent point (beginning or end of parabola), see picture below. The length of the tangent and the axis of symmetry of the parabola determine the parabola.

Here the corresponding curve parameter can be input.