Static Structural Analysis
The everyday workhorse: will this part break, bend too much, or is it fine?
1. What is it?
Static structural analysis answers one question: you push on a part with a steady force — how much does it bend, and how close does the stress get to breaking it?
"Static" means nothing moves fast and the force doesn't change with time: a shelf holding books, a bracket carrying a motor, a table you stand on. If your load arrives slowly and then stays, this is your domain.
"This bracket holds a 50 kg motor. Will it bend more than 1 mm? Will it crack?"
2. When do I use it?
| Use when | Don't use for |
|---|---|
| Will it break? — compare von Mises stress to yield strength | Load changes with time → [Dynamics](dynamics.md) |
| Will it bend too much? — check deflection against your tolerance | Load is heat → [Thermal](thermal.md) |
| Is it over-designed? — find material you can remove | Slender part in compression → [Buckling](buckling.md) |
| Factor of safety — how many times stronger than needed | Two parts touching → [Contact](contact.md) |
Use cases
| Problem Type | Industry | Example |
|---|---|---|
| Bracket stress analysis | Aerospace/Automotive | Engine mount bracket under combined loading |
| Pressure vessel design | Energy/Chemical | Cylindrical vessel with end caps |
| Plate with hole stress concentration | Aerospace | Aircraft fuselage panel with inspection hole |
| Bolted joint preload | Automotive/Machinery | Flange connection under bolt tension |
| Beam deflection | Civil/Structural | I-beam under distributed load |
| Structural integrity after impact | Automotive | Bumper beam after minor collision |
3. The flow — every action described
Step 1: Design (geometry)
What you do: Draw your part or import a CAD file.
How (macOS Design Studio pipeline):
- Top bar 1. Design or Guided Workflow
- In Design Studio 2.0 load a preset (shaft, block, …), build an SDF solid,
- Press Continue to Conditions — stay on the seven-stage path. Do not jump
- Full walkthrough: [Design Studio 7-stage pipeline](design-studio-pipeline.md)
or sculpt. This writes a native Hex8 mesh.
to Solver Hub yet.
How (sketch / import):
- Pick a primitive (rectangle, circle, L-beam, etc.) or
- Click Import → choose
.step,.iges,.stl, or.inp
Why: The solver needs to know the shape. Start simple — you can add holes and fillets later.
Step 2: Boundary (material + supports + loads)
What you do: Tell FEA Lab what it's made of, how it's held, and what pushes.
How:
- Click Boundary tab
- Material: Pick from the library (Steel, Aluminum, Titanium, etc.) or
- Supports (BCs): Click faces/edges that are fixed — "this face is bolted"
- Loads: Click faces/edges and apply force or pressure — "500 N downward"
define your own (E, ν, ρ, yield strength)
Why: The solver needs to know what's held still and what's pushing. Without both, the answer is meaningless.
Step 3: Mesh
What you do: Cut the part into small cells.
How:
- Click Mesh tab
- Adjust mesh size (smaller = more accurate but slower)
- Click Generate
Why: The solver works on tiny triangles/quads. More cells = better answer but slower. Start coarse, refine if needed.
Step 4: Simulate → Results
What you do: Run the solver and read the answer.
How:
- Click Simulate tab
- Click Run
- Wait for convergence (seconds to minutes)
Why: This is where the math happens. You'll see:
- Displacement contour — how much it bends (rainbow colors)
- von Mises stress — how close to yielding
- Verdict — SAFE / MARGINAL / FAIL (if yield strength declared)
4. Reading your results
Displacement (bending)
| Color | Meaning |
|---|---|
| Blue | Little movement |
| Red | Lots of movement |
Good: Deflection is small relative to your part size. Bad: Deflection exceeds your tolerance (e.g., > 1 mm for a bracket).
von Mises stress
| Color | Meaning |
|---|---|
| Blue | Low stress (safe) |
| Red | High stress (close to yielding) |
Good: Max stress < yield strength / safety factor. Bad: Max stress > yield strength → permanent deformation or failure.
Verdict
| Verdict | Meaning |
|---|---|
| SAFE | Stress is well below yield |
| MARGINAL | Stress is close to yield — check your safety factor |
| FAIL | Stress exceeds yield — redesign needed |
Important: A verdict only appears if you declared a yield strength. Without one, you get the numbers with an explicit "no verdict" note.
5. Boundaries of truth
What's validated
| Case | Reference | Error |
|---|---|---|
| NAEMS LE1 (cantilever) | Analytical | < 1% |
| NAEMS CSM (Cook's membrane) | Published | < 2% |
| Patch test | Exact | Machine precision |
| MITC4 shell | Published | < 3% |
What's NOT covered
- Large deformations — geometry changes significantly under load
- Plastic deformation — permanent denting (see [Nonlinear](#nonlinear))
- Contact — two parts touching (see [Contact](#contact))
- Dynamic loads — forces that change with time (see [Dynamics](dynamics.md))
- Thermal effects — heat causing expansion (see [Thermal](thermal.md))
Nonlinear (J2 Plasticity)
What it is: When stress exceeds yield, the material deforms permanently. The analysis tracks this and redistributes stress.
When to use it: You expect yielding and want to know the final shape and residual stress.
Status: ⚠️ Beta — automatic cutback/retry is wired, but restart, large-strain kinematics, and energy checks are not yet production-qualified.
Contact
What it is: Two parts touch and press against each other. The solver finds the contact area and prevents penetration.
When to use it: Bolted joints, press fits, sliding surfaces, impact.
Status: ⚠️ Beta — 2D frictionless small-sliding is production; 3D contact passes Hertz and patch gates but finite sliding, self-contact, robust friction, impact, and restart are not production-qualified.
Common mistakes
| Mistake | Fix |
|---|---|
| Forgot to apply a support | Add at least one fixed face |
| Forgot to apply a load | Add at least one force or pressure |
| Mesh too coarse | Refine and re-run — check convergence |
| No yield strength declared | Add material properties to get a verdict |
| Point load on a mesh node | Use a small face instead — Saint-Venant principle |
See also
- [Dynamics](dynamics.md) — when loads change with time
- [Thermal](thermal.md) — when heat matters
- [Buckling](buckling.md) — when compression causes sudden collapse
- [Fatigue](vibration-fatigue.md) — when loads repeat millions of times
Keep exploring
Open the interactive workspace — mesh, solve, validate and export in the browser.
Start a guided solve