Abaqus Thermal Analysis Workflow

Heat transfer analysis for steady-state or transient temperature distribution. Use when user needs temperature field without mechanical stress.

When to Use This Skill

Route here when user mentions:

"Heat transfer analysis", "temperature distribution"
"How hot will it get?", "thermal analysis"
"Conduction", "convection", "radiation"
"Heat sink design", "cooling analysis"
"Steady-state temperature", "transient heating/cooling"

Route elsewhere:

Thermal stress (temperature causing deformation) → /abaqus-coupled-analysis
Just stress analysis → /abaqus-static-analysis
Temperature as initial condition only → /abaqus-field

Prerequisites

Before thermal analysis:

Geometry defined
Thermal conductivity (k) - required for all thermal analysis
For transient: also need density (ρ) and specific heat (cp)

Workflow: Thermal Analysis

Step 1: Understand User's Goal

Ask if unclear:

Steady-state or transient? Final equilibrium vs temperature over time?
Boundary temperatures? Fixed temperature surfaces?
Convection? Film coefficient and ambient temperature?
Heat sources? Applied heat flux or internal heat generation?

Step 2: Choose Analysis Type

| User Wants | Analysis Type | |------------|---------------| | Final equilibrium temperature | STEADY_STATE | | Temperature vs time history | TRANSIENT | | Cool-down or heat-up time | TRANSIENT | | Just the end result | STEADY_STATE |

Decision rule: Use steady-state unless user needs temperature history or time-dependent behavior.

Step 3: Define Thermal Material Properties

| Property | Required For | Units (SI-mm) | |----------|--------------|---------------| | Conductivity (k) | All thermal | mW/(mm·K) | | Specific heat (cp) | Transient | mJ/(tonne·K) | | Density (ρ) | Transient | tonne/mm³ |

Common materials (SI-mm units):

| Material | k | cp | ρ | |----------|---|----|----| | Steel | 50 | 5.0e11 | 7.85e-9 | | Aluminum | 167 | 9.0e11 | 2.70e-9 | | Copper | 385 | 3.85e11 | 8.96e-9 |

Step 4: Apply Thermal Boundary Conditions

| BC Type | Use For | Required Inputs | |---------|---------|-----------------| | TemperatureBC | Fixed temperature surface | Temperature value | | FilmCondition | Convection to ambient | Film coeff, sink temp | | SurfaceHeatFlux | Heat input | Flux magnitude (mW/mm²) | | RadiationToAmbient | Radiation cooling | Emissivity, ambient temp | | BodyHeatFlux | Internal heat generation | Volumetric heat rate |

Minimum requirement: At least one temperature BC or heat flux boundary.

Step 5: Create Heat Transfer Step

| Parameter | Steady-State | Transient | |-----------|--------------|-----------| | response | STEADY_STATE | TRANSIENT | | timePeriod | 1.0 (arbitrary) | Actual duration (s) | | initialInc | - | Start increment | | maxInc | - | Largest allowed increment | | deltmx | - | Max temp change per increment |

Step 6: Mesh with Heat Transfer Elements

| Element | Use | |---------|-----| | DC3D8 | Standard 8-node hex (recommended) | | DC3D4 | 4-node tet (for complex geometry) | | DC3D20 | 20-node hex (high accuracy) |

Note: Heat transfer elements (DC*) are different from structural elements (C3D*).

Step 7: Run Analysis and Extract Results

Request these field outputs:

NT - Nodal temperature
HFL - Heat flux vector
RFL - Reaction heat flux
HFLM - Heat flux magnitude

Validation Checklist

After analysis, verify:

[ ] Temperature range is physically reasonable
[ ] Heat balance: flux in ≈ flux out (steady-state)
[ ] No unexpected hot/cold spots
[ ] Transient: temperature stabilizes by end of analysis

Troubleshooting

| Problem | Likely Cause | Solution | |---------|--------------|----------| | Temperature oscillation | Large increments in transient | Reduce maxInc or deltmx | | Non-physical temperature | Unit mismatch | Verify k, cp, ρ units | | No heat flow | Missing BC or bad region | Check boundary conditions | | Negative temperature (Kelvin) | Bad setup | Review initial conditions |

Related Skills

/abaqus-coupled-analysis - Thermal + structural (thermomechanical)
/abaqus-material - Thermal material properties
/abaqus-field - Initial temperature fields

Code Patterns

For API syntax and code examples, see: