NAS319 - Principles of Fatigue Analysis

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A state of the art perspective of how practical fatigue calculations are implemented within computer based environments. Alternative environments will be available including Patran, MSC Nastran (from 2013 onwards) and non-product based (Microsoft Excel and command prompt driven).This course will include numerous hands-on fatigue exercises as well as fully computerized approaches.
3 days
Pre-requisites : 
The course will give a basic overview of the methods – but from a quite unconventional perspective (concept rather than equation driven). So no prior knowledge of fatigue analysis techniques or dynamics is required. The latest fundamental developments (theories and implementations) in the field will also be presented.
Day 1
  • History of Fatigue Methods and Their Integration into the CAE Environment
  • The concept of FE Based Fatigue Analysis
  • Background to Dynamics For Fatigue Analysis
  • Step By Step Process For Static and Dynamic Models (Both Time and Frequency Domains)
  • Background Fatigue (Stress Based)
  • Materials Considerations
  • Loading Considerations
  • Stress-Life Based Fatigue in More Detail
  • Strain-Life Based Fatigue
  • Fracture Mechanics and Crack Propagation (Brief Treatment Only)
  • Accelerated Testing Techniques
  • Composites and Non-Metallic Materials
  • An Introduction to Weld Analysis, Wheels Fatigue, Multiaxial Fatigue and MBS
  • Offshore Structures and Fatigue
Day 2
  • Vibration Environments - Random v Deterministic
  • Frequency v Time Domain
  • System Transfer Functions (Frequency Domain)
  • How Transfer Functions Work
  • FFTs and PSDs
  • Calculating PSDs From Time Signals - Buffers and Window Averaging
  • Classifying Time Signals and PSDs
  • Statistics, Probability, and Reliability
  • Loads and “Cross PSDs”
  • Gaussian, Random, and Stationary Data
  • Zero and Peak Crossing Rates, Irregularity Factor, Root Mean Square (RMS) Value & Moments
  • Hand Calculations From a PSD
  • Options For Calculating Fatigue Life From PSDs

Day 3


  • Time Based Methods implemented with computers
  • - Static
  • - Transient
  • - Modal Participation Factor
  • Frequency Based Methods implemented with computers
  • - PSD Based Fatigue
  • Workshops on MSC Fatigue
  • Workshops on Nastran Embedded Fatigue
  • Fatigue Optimization with Nastran Embedded Fatigue
Additional Training Deliverable
  • Electronic copies of the Training material
  • Electronic copies of numerous case studies, technical publications and fatigue theory notes
  • Interactive Discussions on Best Practices and examples from the Field, throughout the sessions
  • Training Certificate, signed by the trainer
  • Laptops / Desktops will be provided during the training for Workshops, with software and licenses
  • Lunch and Coffee
  • MSC souvenirs