Manufacturing Process Simulation
Residual stress, distortion, and thermal history from welding, casting, and additive manufacturing.
1. What is it?
Manufacturing process simulation predicts the residual stress and distortion that remain after fabrication:
- Eigenstrain method: models the plastic strain induced by thermal processes (welding, casting, quenching).
- Thermal history: tracks temperature evolution during the process.
- Distortion prediction: calculates the final shape after cooling.
"This welded joint: what's the residual stress? Will the part distort beyond tolerance?"
2. When do I use it?
| Use when | Don't use for |
|---|---|
| Welding residual stress | In-service loading (use Static Structural) |
| Casting distortion | Dynamic events (use Explicit Dynamics) |
| Quench distortion | Steady-state thermal (use Thermal) |
| Additive manufacturing residual stress | Crack growth (use Fracture) |
3. The flow — every action described
Step 1: Design (geometry)
What you do: Draw the part and the heat source path.
How:
- Click Design tab
- Create or import the part geometry
- Define the weld path or heat source trajectory
Why: The solver needs to know where the heat is applied.
Step 2: Boundary (material + thermal + mechanical)
What you do: Define material properties and process parameters.
How:
- Click Boundary tab
- Material: Thermal conductivity k, specific heat cₚ, density ρ, yield strength σY(T)
- Thermal BCs: Initial temperature, convection, radiation
- Mechanical BCs: Fixtures and clamps during process
- Heat source: Power, velocity, efficiency
Why: The thermal cycle determines the eigenstrain and residual stress.
Step 3: Mesh
What you do: Cut the part into small cells.
How:
- Click Mesh tab
- Refine mesh along the weld path
- Click Generate
Why: Thermal gradients are steep near the heat source.
Step 4: Simulate → Manufacturing
What you do: Run the manufacturing process simulation.
How:
- Click Simulate tab
- Select Manufacturing
- Set process type (welding, casting, quenching)
- Set time step and duration
- Click Run
Why: The solver applies the thermal cycle and computes the resulting eigenstrain.
Step 5: Results
What you do: Read the residual stress and distortion.
How:
- Click Results tab
- View residual stress contour — where is it tensile?
- View distortion — how much did it warp?
- View plastic strain — where did yielding occur?
Why: Residual stress affects fatigue life and distortion affects fit.
4. Reading your results
Residual stress
| Color | Meaning |
|---|---|
| Blue | Compressive residual stress |
| Red | Tensile residual stress |
Good: Compressive residual stress at surface (improves fatigue life). Bad: High tensile residual stress — risk of stress corrosion cracking.
Distortion
| Color | Meaning |
|---|---|
| Blue | Little movement |
| Red | Large distortion |
Good: Distortion is within tolerance. Bad: Distortion exceeds tolerance — adjust fixtures or process.
5. Boundaries of truth
What's validated
| Case | Reference | Error |
|---|---|---|
| Free-bar thermal contraction | σ = E·α·ΔT/(1−ν) | Exact |
| Deposition-quench superposition | Linear superposition | < 1% |
What's NOT covered
- Phase transformations — austenite → martensite
- Microstructure evolution — grain growth
- Multi-pass welding — interpass temperature
- Support structure removal — additive manufacturing
- Creep during cooling — high-temperature relaxation
Common mistakes
| Mistake | Fix |
|---|---|
| Missing thermal properties | Add k, cₚ, ρ to material |
| No mechanical constraints | Add fixtures to prevent rigid body motion |
| Coarse mesh at heat source | Refine mesh along weld path |
| Wrong heat source parameters | Calibrate power and velocity |
| No yield strength vs temperature | Add temperature-dependent σY |
See also
- [Thermal](thermal.md) — for temperature distribution
- [Static Structural](static-structural.md) — for in-service loading
- [Fatigue](vibration-fatigue.md) — for residual stress effects on life
Keep exploring
Open the interactive workspace — mesh, solve, validate and export in the browser.
Start a guided solve