AutoStirrups - Automatic stirrup distribution

AutoStirrups automates stirrup generation in concrete structural elements using either a parametric setup or an existing stirrup from the model. The tool speeds up detailing and reduces manual variation between similar elements.

General Description

The add-in lets users choose between automatic creation and distribution based on a model stirrup template. It includes bar, cover, offset, spacing, and distribution-range settings, plus optional writing of output values into model parameters.

Key Features

• Two stirrup sources: Auto Create builds the shape from your bar/cover settings; From Model copies an existing stirrup as a template.
• Bar and cover setup: Bar type, cover type, and start/end hook.
• Spacing modes: Uniform, Start + Center (symmetric end zones plus a center fill), and Custom zone layout.
• Face limits and custom range: Bound the distribution zone by picking faces or explicit start/end points.
• Single or multiple RebarSet output.
• Parameter writing: Can write the distribution text and/or a layer value into element parameters.
• Profiles: Save and reuse a full configuration.

Requirements

• Works on structural elements that can host a rebar stirrup (columns, beams, and similar concrete elements).
• "From Model" mode requires the reference stirrup(s) to be shape-driven; free-form rebar is rejected.

Usage Procedure

1. Open Auto Stirrups from the Structure panel on the Frata ribbon tab.
2. On the Setup tab, under Stirrup Source choose Auto Create (define bar type and shape automatically) or From Model (distribute an existing stirrup) — for From Model, press Pick Stirrup and select one or more reference stirrups.
3. Configure Bar & Cover Configuration (bar type, cover type, start/end hook) and Offsets.
4. Switch to the Spacing & Limits tab and choose a spacing mode: Uniform (single spacing value), Start + Center (symmetric start zones plus a center max-spacing that fills the remaining span), or Custom (build a zone table with + Add Zone, each row defining a count and spacing).
5. Optionally enable face limits to bound the zone by picking one or two faces, or use Distribution Range to pick explicit start/end points.
6. Choose the output option: Single RebarSet or Multiple RebarSets.
7. Optionally enable Write to Parameter to store the distribution text in an element parameter (with unit, decimals, and a live preview), and/or Assign Layer to write a default value into a layer parameter.
8. Save the setup as a profile if you plan to reuse it, then press Execute. A confirmation message reports how many stirrups were created.

Recommendations

• If a "From Model" reference stirrup isn't shape-driven, it's rejected with a message naming the stirrup that failed.
• "Delete model stirrup(s) after distribution" removes the original reference stirrup once the new ones are created — confirm that's intended before running.
• Save recurring bar/cover/spacing setups as a profile instead of reconfiguring them on every element.

Frequently Asked Questions

What's the difference between "Auto Create" and "From Model"? Auto Create builds the stirrup shape from the bar/cover/hook settings in the dialog. From Model copies the geometry of an existing stirrup you pick in the model and uses it as the template.

I got the message "The rebar '...' could not be distributed. It was not modeled as a valid shape-driven element." What does that mean? The stirrup picked in "From Model" mode is free-form rebar, not shape-driven. Only shape-driven stirrups or standard bars can be used as a template.

What's the difference between "Start + Center" and "Custom" spacing? Start + Center applies the same zone symmetrically at both ends and fills the remaining span at one max spacing. Custom lets you build an arbitrary sequence of zones, each with its own count and spacing, for asymmetric layouts.

Can I reuse the same configuration on other elements? Yes — save the current setup as a profile at the top of the dialog and select it again next time you open Auto Stirrups.