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.