Abaqus Field Skill

This skill defines initial conditions and predefined fields in Abaqus. Use it to set starting states or import results from previous analyses.

When to Use This Skill

Route here when user mentions:

• "initial temperature", "starting temperature", "the part starts at..."
• "pre-stress", "residual stress", "initial stress"
• "initial velocity" (for impact/explicit dynamics)
• "import temperature from thermal analysis"
• "transfer results from previous analysis"
• "bolt pre-tension", "bolt preload"

Route elsewhere:

• Fixed temperature boundary conditions → /abaqus-bc
• Heat flux, convection, radiation loads → /abaqus-load
• Time-varying fields via amplitude → /abaqus-amplitude

Key Decisions

Field Type Selection

| User Need | Field Type | Typical Use | |-----------|------------|-------------| | Starting temperature | Temperature | Thermal stress from uniform T | | Residual stress | Stress | Pre-stressed members | | Impact velocity | Velocity | Explicit dynamics | | From other analysis | Predefined Temperature | Sequential thermal-structural | | Custom variable | Predefined Field | User-defined behaviors |

Distribution Type

| Type | When to Use | |------|-------------| | UNIFORM | Same value everywhere | | FROM_FILE | Import from ODB or FIL | | ANALYTICAL_FIELD | Expression-based (X, Y, Z) | | USER_DEFINED | Via user subroutine |

What to Ask User

If information is missing, ask:

1. What initial condition? Temperature, stress, velocity, or custom field?
2. Uniform or varying? Same value everywhere or position-dependent?
3. Import from ODB? If transferring, which file/step/frame?
4. Region? Entire model or specific region?
5. Value(s)? Magnitude, stress components, or velocity vector?

Workflow: Setting Up Fields

Step 1: Identify Field Type

Match user request to field type:

• Temperature values → Temperature field
• Stress state → Stress field
• Moving parts → Velocity field
• Previous analysis results → FROM_FILE distribution

Step 2: Define Region

Determine where the field applies:

• Entire model (assembly set)
• Specific part instance
• Element set or node set

Step 3: Set Values or Import

For uniform fields: specify single magnitude or component values. For imported fields: ODB path, step name, increment number.

Step 4: Verify Step

Initial conditions use createStepName='Initial'. Predefined fields in analysis steps use the step name.

Sequential Thermal-Structural Workflow

1. Run thermal analysis, save ODB
2. Import temperature as predefined field in structural model
3. Temperature causes thermal strain (requires expansion coefficient)

Key Parameters

| Parameter | Notes | |-----------|-------| | createStepName | 'Initial' for initial conditions, step name for predefined | | distributionType | UNIFORM, FROM_FILE, ANALYTICAL_FIELD | | fileName | ODB path for FROM_FILE distribution | | beginStep/endStep | Frame selection for ODB import |

Validation Checklist

• [ ] Correct field type for the physics
• [ ] Region covers intended elements/nodes
• [ ] Step name is correct (Initial vs analysis step)
• [ ] For FROM_FILE: ODB exists and contains required data
• [ ] For thermal stress: material has expansion coefficient

Troubleshooting

| Problem | Likely Cause | Solution | |---------|--------------|----------| | Field not applied | Wrong region or step | Verify region covers elements | | Cannot read from ODB | ODB locked or wrong path | Close other sessions, check path | | Temperature mismatch | Mesh incompatibility | Use mapping tolerance options | | Stress equilibrium error | Stress not self-equilibrating | Review stress field consistency |

Code Patterns

For API syntax and code examples, see references/ folder.