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Getting Started

The ETABS and SAP2000 agents let you build structural models through conversation. Describe what you want, and the agent creates the model automatically.
Pro Tip: Use @ to search building codes while writing prompts. Try @ASCE 7 for wind loads or @ACI 318 for concrete design.

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Agent in Action

Watch the SAP2000 Agent build a steel structure while running through the local Stru AI app:
The Stru AI app runs on your machine and connects to your local ETABS/SAP2000 installation. You chat through the browser while the agent controls the software directly on your computer.
The interface shows:
  • Center: Interactive 3D model views from SAP2000/ETABS - click to select elements for modification
  • Right panel: Agent’s explanation of what was built and validation summary
  • Bottom: Task breakdown with completed (✓) and in-progress (⚡) steps

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ETABS vs SAP2000: Which Agent?

ETABS Agent

Choose for:
  • Buildings (high-rise, concrete frames, shear walls)
  • Floor diaphragms and vertical load distribution
  • Building-specific seismic and wind design
  • Story-based modeling workflows

SAP2000 Agent

Choose for:
  • Bridges, trusses, space frames
  • Industrial structures and towers
  • Long-span systems and stadiums
  • General-purpose structural analysis

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Writing Effective Prompts

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The Golden Rule

Either be specific OR explicitly give the agent discretion. Avoid vague prompts. 
Create a 4-story building:
- Plan: 120ft x 80ft
- Bays: 4 @ 30ft in X, 4 @ 20ft in Y
- Story heights: 15ft ground, 12ft typical
- Columns: W14x120
- Beams: W21x50
- Units: kip-ft

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Key Prompt Elements

Always include units in your first prompt:✅ “Use kip-ft units for this model…”Prevents unit confusion later.
For complex structures, work incrementally:
First, create the basic frame geometry.
[Review screenshot]
Now add X-bracing to perimeter frames.
[Review again]
Finally, apply gravity loads.
Specify load directions clearly:✅ “Apply loads in gravity direction (downward)”✅ “Wind loads in Global Y direction”✅ “Distributed along member length”

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Common Use Cases

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Concrete Building Frame

Create a 5-story reinforced concrete frame:
- Plan: 100ft x 75ft
- 5 bays @ 20ft in X, 5 bays @ 15ft in Y
- Story height: 12ft typical
- Columns: 24"x24", Beams: 18"x24"
- Concrete: f'c = 4000 psi
- Apply loads: DL=120psf, LL=60psf

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Adding Shear Walls

Add concrete shear walls to the existing frame:
- Walls on gridlines A and D (perimeter)
- Wall thickness: 12"
- Height: Full building height
- Connect to existing frame with rigid connections

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Modifying Existing Model

Option 1: Describe the changes
Change all columns on levels 3-5 to 24"x30".
Keep levels 1-2 as 24"x24". Show before/after comparison.
Option 2: Select and modify Click to select specific columns in the 3D viewer, then: “Change these selected columns to 24”x30""

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Floor Diaphragm Modeling

Add floor diaphragms at all levels:
- Slab thickness: 8"
- Diaphragm type: Rigid
- Include openings for stairs and elevator shafts
- Apply floor loads: DL=120psf, LL=60psf

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Advanced Usage

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Study and Recreate Existing Models

The agent can analyze existing models and recreate them with modifications: 
Open 'Existing_Building.sdb' and study its geometry, sections,
and loads. Then create a similar model but with:
- 20% taller story heights
- Updated to ASCE 7-22 wind loads
- Member sizes optimized for new loads
Use cases: Modernize old models to new code provisions, create design variations, or standardize legacy projects.

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Compare Two Models

Compare different design options: 
Compare 'Option_A.sdb' and 'Option_B.sdb':
1. Total steel weight difference
2. Drift ratios under lateral loads
3. Foundation reactions comparison
4. Cost implications of member size differences
Use cases: Design optimization, value engineering studies, structural system selection, and code compliance verification.

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Use Sketches and Floor Plans

Upload drawings to convey information: 
I'm attaching a floor plan sketch. Create a 3-story model
based on this layout. Use W14 columns and W18 beams.
Story height: 12ft.
What you can upload: Hand-drawn sketches, PDF floor plans, marked-up elevations, or structural diagrams. The agent interprets dimensions, grid layouts, and structural intent from images.

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Parametric Design and Iterations

Rapidly generate design variations for optimization studies, value engineering, and sensitivity analysis.
Lateral system comparison
Model the same building with three lateral systems:
1. Perimeter moment frames
2. Interior braced frames
3. Concrete shear walls at core

Compare drift, period, material quantities, and foundation demands.
Floor system optimization
Create 4 variations of floor framing:
1. Post-tensioned slab (8" thick)
2. Two-way concrete slab (10" thick)
3. One-way joist system (24" depth)
4. Composite steel deck (3" deck + 12" beams)

Compare cost, weight, and floor-to-floor height.
Building height study
Create iterations for 4, 6, 8, and 10 story variations:
- Keep same footprint (120ft x 80ft)
- Adjust column sizes for increased height
- Compare seismic base shear and drift
- Report steel/concrete quantities per floor
The agent handles the repetitive modeling work, letting you focus on engineering decisions.

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Best Practices

Always specify units firstInclude units in your opening prompt: “Create a model using kip-ft units…”Build geometry before loadsCreate structure first → Review screenshot → Apply loads → Verify patterns → Run analysisSave incrementallySave at major milestones: “Save as ‘Building_BaseFrame_v1.sdb’ before we modify the lateral system”

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Troubleshooting

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Model Doesn’t Look Right

Show me:
- Isometric view
- Plan view at level 2
- Elevation along gridline A

List all frame members with their coordinates and sections.

This isn't quite right. Let's create a new model.
This time, use 4 bays @ 25ft instead of 5 bays @ 20ft.

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Agent Seems Stuck

If the agent stops responding, keeps repeating the same step, or gets caught in a loop, work through the fixes below from top to bottom — start with a prompt nudge, and only restart the client or model if prompts don’t help.
Recovery ladder: (1) Ask for status → (2) Redirect with a prompt → (3) Simplify or break it down → (4) Start the task from scratch → (5) Restart the client → (6) Close the model and start a fresh session. Each step is a bigger reset than the last.

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Try a Prompt First

See where the agent is before changing anything:
What's the current status? Which step are you on, and
are you stuck or waiting on something?
Nudge the agent to step back instead of pushing the same path:
This approach doesn't seem to be working. Stop and
rethink it. Explain a simpler plan before you make any
more changes, then proceed once the plan looks right.
Strip the task down to the essentials and add detail later:
Let's pause. Just create the basic frame geometry
without loads for now.
Instead of one complex prompt, use a sequence and review between steps:
  1. Create geometry
  2. Add lateral system
  3. Apply loads
  4. Run analysis
If the model is in a bad state, have the agent abandon it and rebuild cleanly:
Let's start over from scratch. Discard the current
progress, create a new model, and rebuild it step by
step. Confirm each step with a screenshot before moving on.

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Reset the Session

If prompts aren’t getting through, the connection between the app and ETABS/SAP2000 may have hung. Reset it.
Open the Client dropdown in the top-right of the app and choose Restart client. This reconnects the app to ETABS/SAP2000 without closing your model. Wait for the green dot, then send your prompt again.
Restart client from the Client dropdown
If a restart doesn’t help, the ETABS/SAP2000 model itself may be in a stuck state:
  1. Stop client from the Client dropdown.
  2. Close the model in ETABS/SAP2000 (save first if you want to keep it).
  3. Reopen ETABS/SAP2000, then Restart client and wait for the green dot.
  4. Ask the agent to reopen your saved model, or start a fresh build.
A clean model and a fresh client connection clears the large majority of stuck states.
If the agent is still stuck after a full restart, click Update (top-right) to make sure you’re on the latest app version, then try again. If the problem persists, email bhosh@stru.ai with a short description and a screenshot.

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Loads Not Applied Correctly

List all load patterns and show which members have
loads in the DEAD case.

Verify the loads are applied downward (gravity).
Reapply if the direction is wrong.

Screenshot with load arrows visible.

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Real-World Workflow

Complete design sessions showing iteration and refinement:
1

Initial Model

Create a 4-story office building:
- 150ft x 100ft plan
- 5 bays @ 30ft in long direction
- 4 bays @ 25ft in short direction
- Story heights: 15ft ground, 13ft typical
- Use engineering judgment for member sizes
- Units: kip-ft
Agent creates model with W14x176 columns, W24x62 beams
2

Optimize

Beams seem heavy. Try W21x50 for levels 2-4,
keep W24x62 at ground only.
Agent updates sections
3

Add Lateral System

Make perimeter frames on gridlines A and E moment-connected
for lateral resistance.
Agent modifies connections
4

Apply Loads

Floor loads:
- Dead: 100psf (slab + MEP + ceiling)
- Live: 50psf (office)
- Roof: Dead 80psf, Live 20psf

Create ASCE 7 gravity combinations.
Agent applies loads and combinations
5

Verify

Before analysis, show:
1. Isometric with loads visible
2. Total applied loads by level
3. List of load combinations
Agent provides verification package
6

Save

Save as 'Office_Gravity_Rev1.edb'
Agent saves and provides download link

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Tips for Success

  • Iterate freely - Don’t expect perfection first try. Refine with follow-ups: “Can you adjust the bay spacing to be more uniform?”
  • Interactive selection - Click elements in the 3D viewer to select them, then ask the agent to modify your selection
  • Request screenshots - Ask for visual verification at key stages: “Show isometric view to confirm bracing layout”
  • Upload references - Attach floor plans, sketches, or existing models to guide the agent and convey complex information visually
  • Compare options - Generate multiple design variations quickly for value engineering and optimization studies

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Next Steps

Try Online

Explore agent capabilities online - no installation neededGo to app.stru.ai

Get Full Access

Set up the Stru AI app on your machine for production workDownload Stru AI App

Upload a Sketch

Try creating a model from a floor plan or structural drawing

Run a Parametric Study

Generate 3-5 design variations and compare them

Study Existing Model

Have the agent analyze and explain one of your existing models

Reference Codes

Use @ in prompts to search ASCE 7, ACI 318, AISC 360, IBC
Questions? Email bhosh@stru.ai or book a call to discuss your use case.