Getting Started with Cimbra

Cimbra is a structural optimization tool for precast concrete design. It finds the best designs for your chosen objective — weight, cost, or embodied carbon — all verified against ACI 318-19.

How It Works

Add mold designs and materials you typically work with to the Mold and Material Libraries
Create a project and define your spans and loads
Select materials from the library or enter custom properties
Choose mold geometries to optimize against (or let the optimizer choose freely)
Run the optimization — Cimbra finds optimal designs in seconds
Review results with full structural verification (moment, shear, deflection, serviceability)
Export a PDF report or CSV data

Key Concepts

Single Element vs. Project Level Optimization

Element level: Limit optimization problem to a single element by only entering data in the first line of the Input Project Data table.
Project level (default): Define a multi-span problem with multiple rows of the Input Project Data table with different loads per span. Optimal results are generated for each span.

Note: The more complex a problem you define, the slower the optimization, however no optimization should take longer than 2-3 minutes.

Problem Types

Prestressed: Includes prestress strands as design variables.
Reinforced Concrete (RC): Passive rebar only. Create and select a mold with a strand count of 0 to run an optimization without prestressing.

Mold Catalog vs. Free Optimization

Catalog mode: Select molds from your library — the optimizer finds the best design within each mold's geometry constraints.
Free optimization: Molds can we defined with a broader geometric design space to explore (think flatbed mold with defined width and max depth but no constraint on number of ribs for a multiribbed slab where additional forms are constructed on top of the bed). Allowing the optimizer to explore wider ranges of geometry is a great way to develop new product designs or push the boundaries of your existing mold library.

Getting Started