Fatigue Life Predictor Skill

Purpose

The Fatigue Life Predictor Skill estimates fatigue life of medical implants and load-bearing devices using established methodologies per ASTM and ISO standards, supporting design verification and regulatory submissions.

Capabilities

• S-N curve generation and analysis
• Strain-life fatigue modeling
• Multiaxial fatigue assessment
• Fretting fatigue evaluation
• Corrosion fatigue considerations
• Goodman diagram construction
• Run-out criteria application
• Notch sensitivity analysis
• Statistical treatment of fatigue data
• Design allowable determination
• Fatigue test correlation

Usage Guidelines

When to Use

• Predicting implant fatigue life
• Designing fatigue testing protocols
• Correlating FEA with bench testing
• Supporting design verification

Prerequisites

• Stress analysis completed
• Material fatigue properties available
• Loading spectrum defined
• Surface finish characterized

Best Practices

• Use appropriate fatigue methodology for loading type
• Account for mean stress effects
• Consider physiological environment effects
• Correlate predictions with bench testing

Process Integration

This skill integrates with the following processes:

• Finite Element Analysis for Medical Devices
• Orthopedic Implant Biomechanical Testing
• Design Control Process Implementation
• Verification and Validation Test Planning

Dependencies

• fe-safe software
• ANSYS nCode
• ASTM F1717/F2077 standards
• Material fatigue databases
• FEA stress results

Configuration

fatigue-life-predictor:
  methodologies:
    - stress-life
    - strain-life
    - fracture-mechanics
  loading-types:
    - constant-amplitude
    - variable-amplitude
    - multiaxial
  mean-stress-corrections:
    - Goodman
    - Gerber
    - Morrow
  environment:
    - air
    - saline
    - body-fluid

Output Artifacts

• Fatigue life predictions
• S-N curves
• Goodman diagrams
• Safety factor calculations
• Test correlation reports
• Design recommendations
• Statistical analysis results
• Regulatory submission summaries

Quality Criteria

• Methodology appropriate for loading conditions
• Material data from validated sources
• Mean stress effects properly accounted
• Environmental factors considered
• Predictions correlated with testing
• Documentation supports regulatory review