How to display the outer distance between rebars of a tapered curved bar group using "Reinforcement mark" in drawings?

Environment

Not environment-specific

Attachments

Question:
We have created a concrete slab with one side shaped as a segment of a circle and reinforced it with a tapered curve rebar group. How can we place a rebar group mark so that it would represent the outer target cc distance between rebars?

Image

Answer:

By default Tekla Structures automatically calculates the smallest distance between rebars - in this case the inner distance between rebars, and there is no automatic way to force it to measure “target cc” distance from the outer side of the bars.

This tutorial gives a workaround solution on how to do it.

There are two unknown values in the equation (angle and inner distance) on how to determine the outer distance between rebars, so it is hard to find the value that needs to be entered in the rebar spacing value field in Template Editor. In this case, the fastest way to determine this distance is just entering some values and then checking the outer distance between rebars, enter and check, enter and check and so on until you find a distance which is close enough. In about 10 cycles it is possible to find a rather close distance. In this example, 200 mm was chosen as the target value. A value of 200.6 mm was achieved by entering a value of 107.2 mm when the creation method was set to “By exact spacing value with flexible first and last space”.

The next thing that has to be done is to measure the angle between any two rebars in the group. As they are distributed equally, the angles will be equal (except first and last). The easiest way to do this is with the help of construction lines. In this example, 3.7101 degrees.

The measured angle has to be recalculated from degrees to radians. Radians=(degrees*π)/180. In this example, the value is 0.0323767rad.
The template, attached to this article, must be modified. Open the “outer_rebar_mark.tpl” with Template Editor. Then open “Value Field Properties” for “SIN_RAD”. Enter the calculated radians value in the“Formula” field.

Close and save the template. After this, place the template in the “Mark” folder inside the “Model folder” directory. If the “Mark” folder does not exist, create one manually.
Open the created drawing and create “Reinforcement mark” for the rebar group. Modify the “Reinforcement mark” and select the saved template “outer_rebar_mark.tpl”. Click Modify and close the dialog box.

The mark should show “cc outer 200 mm”. If, for example, it shows values like 199 mm or 201 mm, the precision in the rebar group properties dialog box (107.2 mm) must be adjusted.

The attached “outer_rebar_mark.tpl” template can be customized. In this example, it is used only for demonstrational purposes.

To increase the precision of measured angle in the model, go to Tools -> Options -> Options. Under Units and decimals increase the decimal place number for Angle.