Abaqus Static Analysis Workflow

Complete workflow for static structural analysis - stress, displacement, and reaction forces under constant loads.

When to Use This Skill

Route here when user mentions:

"stress analysis", "structural analysis"
"how much will it deflect", "displacement"
"is this strong enough", "strength check"
"factor of safety", "safety factor"
"reaction forces", "support loads"
"simulate a load on this part"

Route elsewhere:

Time-varying loads, impact, vibration → /abaqus-dynamic-analysis
Natural frequencies, resonance → /abaqus-modal-analysis
Temperature effects, thermal stress → /abaqus-coupled-analysis
Heat transfer only → /abaqus-thermal-analysis
Parts touching, friction → /abaqus-contact-analysis

Workflow Steps

Execute these skills in order:

| Step | Skill | Purpose | |------|-------|---------| | 1 | /abaqus-geometry | Create part and assembly | | 2 | /abaqus-material | Define material properties | | 3 | /abaqus-mesh | Generate finite element mesh | | 4 | /abaqus-bc | Apply supports and constraints | | 5 | /abaqus-load | Apply forces and pressures | | 6 | /abaqus-step | Configure analysis step (optional - default is fine) | | 7 | /abaqus-job | Run the analysis | | 8 | /abaqus-odb | Extract results |

What to Ask User

Required Information

| Input | What to Ask | |-------|-------------| | Geometry | "What are the dimensions? (e.g., 100x50x20 mm)" | | Material | "What material? (Steel, Aluminum, or custom E/v)" | | Supports | "How is it supported? (fixed face, pinned points, rollers)" | | Loads | "What loads? (force magnitude, location, direction)" |

Optional (Has Defaults)

| Input | Default | Ask If | |-------|---------|--------| | Mesh size | Auto-calculated | Stress concentrations present | | Element type | C3D8R | Complex curved geometry | | Nonlinear | OFF | Large deformation expected |

Key Decisions

Linear vs Nonlinear Analysis

| Condition | Setting | When | |-----------|---------|------| | Small deformation, linear material | nlgeom=OFF | Displacements < 1% of part size | | Large deformation or rotation | nlgeom=ON | Thin structures, rubber, cables | | Yielding expected | nlgeom=ON + Plasticity | Stress > yield strength |

Default: Start with linear. Switch to nonlinear if convergence issues or large deformation.

What Results to Extract

| User Goal | Output Variables | Acceptance Criteria | |-----------|-----------------|---------------------| | Strength assessment | S (stress), MISES | MISES < yield stress | | Stiffness check | U (displacement) | Max deflection acceptable | | Support sizing | RF (reaction force) | Reactions match applied loads |

Validation Checkpoints

After Each Step

| Step | What to Verify | |------|----------------| | Geometry | Part has cells, no error messages | | Material | Section assigned to all cells | | Mesh | Node count OK (Learning Edition: <=1000) | | BCs | At least one fixed constraint exists | | Loads | Applied to correct surface/point | | Job | Completes without errors in .sta file |

Results Sanity Checks

| Check | Expected | |-------|----------| | Reaction force sum | Approximately equals applied loads | | Displacement magnitude | Physically reasonable | | Stress pattern | Follows logical load path | | Max stress location | At expected concentration points |

Troubleshooting

| Error | Cause | Solution | |-------|-------|----------| | "Zero pivot" | Rigid body motion | Add more BCs to constrain all 6 DOFs | | "Negative eigenvalue" | Buckling or instability | Check BCs, may need stabilization | | "Too many increments" | Load too large | Reduce load or use more increments | | "Equilibrium not achieved" | Convergence failure | Try smaller initial increment | | "Memory exceeded" | Mesh too fine | Increase element size |

Feedback Loops

Mesh fails: Return to geometry, add partitions or simplify
Zero pivot error: Return to BCs, ensure all rigid body modes constrained
Unreasonable results: Verify material properties, check load direction/sign
Stress too high: Either design issue (expected) or incorrect BC/load setup

Code Patterns

For API syntax and code examples, see: