Course Textbook:

Schijve, Jaap, Fatigue of Structures and Materials, Kluwer Academic Publishers, Second Edition, 2009.

Each participant is encouraged to review chapters 1-12 and 18 of the course textbook prior to attending the course to maximize the effectivity of the class time.

Course Includes:

  • A course notebook prepared by your instructor
  • Supplemental material to enhance the subject matter
  • Refreshments served each morning and afternoon

Course Description & Outline:

This is a follow on course to the fundamental Fatigue and Damage Tolerance Analysis course taught by the same instructor. The course provides a review of the fundamental course material plus presentation of the updated material. Advanced topics such as concepts of WFD and LOV, plus methods to evaluate WFD behavior and how to determine LOV for compliance to §§26.21, 26.23 and 25.571, Amendment 25-132 is provided. Example problems are solved real time demonstrating details of these concepts. Guidance for F&DT analyses of various kind of designs, alterations and repairs to fuselage upper and lower lobe, wing and horizontal stabilized are provided. FEM applications for various design requirements such as load transfer in joints, stress distribution in built-up structures, computation of Kt and SIF are discussed. You are encouraged to voluntarily participate in a practicum (see below for more information). A world class inspector will provide a presentation of popular NDT techniques used in aerospace with hands on demonstrations of these techniques. Fracture mechanics of composite material structures along with examples will be presented.

Course Pre-requisite: Fatigue and Damage Tolerance Analysis course.

Practicum: You are encouraged to voluntarily participate in a practicum, which is to make a short live presentation of a F&DT example to demonstrate how you have used the knowledge acquired in the fundamental course. This presentation should be coordinated with the instructor before presentation for review and approval. The proprietary data will be handled appropriately.

Day 1

  • Introduction
  • Review of Original Material (Refresher)
    • Fundamentals
      • Kt, Residual Stresses, S-N curves, SIF, da/dN vs ⌂K, KA, R, G
    • Review of fatigue analysis
    • Lunch
    • Review of crack growth analysis
      • Paris, Forman, Nasgro Eqs., Cracking scenario
    • Review of residual strength analysis
    • FEM applications
      • Load transfer
      • Load distribution
      • Stress concentration factor – Kt
      • Stress Intensity Factor (SIF)

Day 2

  • Practicum
  • Presentation of New Material
    • Introduction to the latest requirements
      • New requirements – Part 26, 25, Examples
  • Lunch
  • WFD Assessment Methodology
    • Multiple Site Damage (MSD)
    • Multiple Element Damage (MED)
      • Various cracking patterns
      • Fatigue analysis
      • Crack growth evaluation
      • Residual strength assessment

Day 3

  • Presentation of New Material (cont.)
    • Limit of Validity (LOV)
    • Widespread Fatigue Damage (WFD)
      • Fatigue scatter
      • Selection process, ISP & SMP
    • New spectrum material (UDRI)
  • Lunch
  • Non-destructive Inspect Testing (NDT)
    • Presentation of NDT techniques
    • Demonstration of ultrasound and eddy current techniques
    • Hands-on exercise for the participants

Day 4

  • Discussion of DTA for RAMs
    • What are the DTA requirements for repairs?
      • Category and requirements
    • What are the DTA requirements for modifications/alterations?
      • Updates to baseline inspections – DTR forms
      • New inspections
    • Antenna installation & repairs to airframe
      • Comparison to SRM
      • New
    • Non-reinforced repairs
      • Blend out, Dent
  • Lunch
  • Fracture Mecahnics of Composite Structures
    • Introduction
    • Examples (Classical & FEA)
  • Closing Remarks