abaqus-static-analysis

# 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: - [Common Patterns](references/common-patterns.md) - [Troubleshooting Guide](references/troubleshooting.md)