Strut-and-Tie Model Design, verified.

AStrutTie designs the concrete members where ordinary beam theory doesn't apply — deep beams, corbels, pier caps, footings, frame corners — with a strut-and-tie model you can see, check, and hand to a reviewer.

Run AStrutTie in your browserFree · Google sign-in · up to 15 nodesSee plans & pricingFree forever · Standard · Pro · Perpetual

Strut — concrete compression
Tie — reinforcement tension
Nodal zone

A strut-and-tie model of a deep beam: compression struts (dashed), a tension tie (solid), and nodal zones where they meet.

✓ 19 automated gate suites · 1414 checks green How we verify →
✓ Cross-verified against independent references — published ACI 318-19 hand calculations, SAP2000, and a from-scratch numpy oracle
✓ Your AI know-how data stays yours — never used to train models for other customers Data policy →

Try it live

Change the load — member forces and required section areas update in real time.

Run live

See the product

Real screens from AStrutTie v2 — the workflow, the checks, the output.

AStrutTie template gallery — **16 D-region templates**Deep beams, corbels, pile caps, pier copings, anchorage zones — a verified strut-tie model in minutes.

AStrutTie required and maximum section bands on the strut-tie model — **Checks you can see**Required vs maximum section area drawn right on the model — the safety margin, visible per member.

AStrutTie Design Review strength-check tables — **Code checks, in the open**Every strut, tie and nodal zone against the design code — pass / fail and safety factor, per member.

AStrutTie 3D strut-and-tie model — **3D strut-and-tie**3D pile caps and pier / abutment grids — the model, the checks and the report in three dimensions.

AStrutTie calculation report output — **A submittable report**A full calculation report — geometry, member forces and code checks — ready to hand in.

AStrutTie stress-flow underlay behind the strut-tie model — **Check against the stress flow**Compare your model to the real stress field (built-in plane-stress FEM) — the hard part of STM, guided.

What it does

The full strut-and-tie model design workflow, from geometry to a submittable report.

16 D-region templates

Footings (spread, pile, abutment, 3D pile cap, pier/abutment grids), deep beams, continuous deep beams, corbels, pier copings, frame corner, anchor plate, PSC anchorage, box girder, lattice girder — a verified strut-tie model in minutes, not hours.

5 design codes

KDS (strength design & limit state), ACI 318, AASHTO LRFD, and Eurocode 2 — strut, tie, and nodal-zone checks with the correct nominal strength for each code.

Truss + plane-solid solvers

Determinate and indeterminate truss analysis, plane-stress FE, principal stress flow, and ESO topology guidance for the model shape.

Reports reviewers accept

Full HTML calculation reports — open in Word or print to PDF — with every check traceable to the code clause.

DXF import

Bring member outlines and truss geometry straight from CAD instead of re-drawing them.

One workspace, web and desktop

The new AStrutTie is one codebase for browser and desktop: a single workspace, a command palette, and one-click auto-fix for failing checks.

AI review assistance — rolling out

A senior-engineer-style read of your computed results — governing members, NG checks, next steps — in plain language. Every number stays the verified solver's; AI never recomputes. You decide, you sign. Model suggestions are in development.

Rebuilt, not repackaged

AStrutTie has been rebuilt from the ground up: the same verified strength equations, in a modern engine that runs in your browser with no install, and on the desktop from the same code.

NG one-click auto-fix — envelope and increase-only, never silently unsafe
Command palette (Ctrl+K) and keyboard-first workflow
Analysis and design checks run locally via WebAssembly — your model stays in the browser

Ready to verify your strut-and-tie model design?

Run AStrutTie in your browser View pricing