TRAINING COURSE CATALOG

Aging Aircraft Course | Aircraft Structural Accidents | Aircraft Composites | Fatigue, Fracture Mech, DTA
Corrosion of Aircraft Structures | Composite Structures | A/C Structural Repair Analysis
Advanced Damage Tolerance Analysis

 

Fatigue, Fracture Mechanics and Damage Tolerance
of Aging and Modern Aircraft Structures

 

COURSE OUTLINE

  • Prologue
  • Cost of Fracture
  • The Danger of Metal Fatigue
    • Early transportation failures from centuries past
      • Bridges
      • Trains
      • Titanic and Liberty ships
      • Wright Flyer, Comet, …
      • F-111 crash
    • What is a Failure? USAF-Navy-FAA-NASA Guidelines
    • Structural Failure Modes
    • Environmentally induced and/or time-dependent failure modes
      • Creep, Fatigue, Corrosion, Wear, Fretting, Hydrogen Embrittlement
    • Synergistic processes
      • Corrosion fatigue, fretting fatigue, SCC, high temperature fatigue
    • Why High Strength materials are weak in fatigue!
    • Crack Initiation and Propagation
    • Design Strategies to combat Metal Fatigue
      • Safe Life
        • Safety Factor fantasies
      • Fail Safe
        • 1. Crack Arrest
        • 2. Multiple Load Path (Structural Redundancy)
        • Design for inspectability
  • Fractography
    • What does a fatigue crack look like?
    • Macro and Micro Aspects
    • Striations and Beach Marks
    • Quantitative and qualitative use
      • Ratchet lines
    • Marker cycles
    • Guides on using Fractography
    • Scanning Electron Microscope
    • Use of fractography to perform failure analysis
  • Stress Concentration Kt, Finishes
    • Stress Concentrations
      • Load Flow Lines (Streamlines): a useful analogy
    • Surface finish
      • Pitfalls in grinding
      • Chrome-plating dangers, zinc and other platings
    • Size effects
      • Leonardo da Vinci
      • Similitude or lack thereof
    • Scatter, Reliability
    • High Temperature Effects
  • Fatigue Life Prediction
    • Cycle parameters
      • Range, amplitude, mean stress, R ratio
    • S-N Curves
      • Endurance Limit is largely a myth: Use Fatigue Strength
      • Fatigue Strength
      • Mean stress effects
      • Constant Life Diagrams, Haigh Diagrams
    • Low cycle fatigue
      • Neuber’s Notch strain analysis
    • Miner’s Myth
      • Extremely limited applicability and lack of defensibility
      • It is not a RULE
    • Fracture Mechanics
      • Griffith Criterion
      • George Irwin, Naval Research Lab: Father of  Fracture Mechanics
      • Stress intensity factor SIF KI
      • Beta factors
      • Residual strength
      • Fracture toughness
        • Effect of thickness, orientation, impact, temperature
        • Dynamic fracture toughness and crashworthiness
      • Crack propagation
      • Thresholds
      • Inspection intervals
      • Classroom problem-solving exercises
      • NDE, detectable crack sizes
        • Visual, eddy current, radiographic, ultrasonic, penetrant, magnetic particle
        • Applicability, comparison
        • POD (Probability of Detection)
        • Reliability of Inspections
        • Case Study: MD-88 uncontained engine failure
      • Initial quality, EIFS equivalent initial flaw size
      • Multiaxial stresses, Mixed mode cracking
    • Short cracks
      • Can be deadly
    • Classroom tutorials in Fracture Mechanics
      • Rigorous, parametric evaluations of various interconnected variables: fracture toughness, initial flaw size, inspection interval, fastener holes, corrosion effects, coldworking, shot-peening, da/dN, material properties C, m, …
    • Damage Tolerance
    • MIL-A-83444 -> MIL-A-87221 -> JSSG2006
      • 1. Fail-safe structure
        • Arrest of a rapidly running crack
        • Safe partial failure of a load path
          • Skin-stringer partnership
          • Titanium crack stoppers
      • 2. Slow crack growth structure
        • Degree of inspectability
      • Initial flaw assumptions
    • Retardation Models
      • Willenborg
      • Wheeler
      • Closure
      • Onera…
    • Continuing damage
    • ASIP, IATP
  • Environmentally Assisted Cracking
    • Corrosion Fatigue
      • Effect of frequency, waveform, hold-time, …
    • Stress Corrosion
      • KIscc
      • SCC ratings for aircraft alloys
      • Case study: SCC of a High Strength Steel Frame in a USNavy Fighter
    • Fretting Fatigue
      • How surface finish, similar materials in contact, slip amplitude, temperature, and environment affect Fretting Fatigue
    • Contact fatigue
      • Gear failures
    • Aging aircraft issues
      • Durability vs Damage Tolerance
      • Multi-Site Damage, Widespread Fatigue Damage
      • The Aloha accident
      • Continued airworthiness
      • Supplemental inspection programs
      • Limit of Validity (LOV)
  • Testing for Substantiation and Data accumulation
    • Cycle Counting methods
      • Rain flow method
    • In-flight loads monitoring
    • Testing
    • Coupons, specimen, component, and Full-Scale
      • Standardized Testing
      • Coupon preparation, precracking guidelines
      • E-399 KIc
      • E-647 da/dN
      • Service duplication Testing
      • Environmental chambers
      • Time compression issues in corrosion fatigue testing
    • Load Spectrum Generation
      • Canned Spectra
        • TWIST, MINITWIST, TURBISTAN, HELIX, FELIX, …
      • Sequence effects
      • Truncation, clipping
    • Scatter, Reliability, Risk management
      • Weibull Paper, Example problem
    • Material Properties & Useful Data handouts and Sources
      • S-N curves
      • Crack initiation data 
      • da/dN crack growth data
      • Fracture Toughness Kcs
      • Data sources and handbooks
      • Journals
  • Special Topics (Optional)
    • Cracking in aircraft engine components
      • ENSIP
      • Sioux City DC-10 crash landing
      • Thermo-mechanical Fatigue
    • Creep Fatigue
    • Thermal Fatigue
      • Concorde
    • Sonic fatigue (Acoustic Fatigue)
    • Fatigue of composites
      • Polymers
    • ARALL, GLARE and other newer materials to fight fatigue
  • Do’s and TABOOs
    • Methods to improve fatigue resistance
    • Clever use of favorable residual stresses
      • Cold-working of holes
      • Shot Peening
      • Residual Stress control measures
    • Bolts, Rivets, Springs, Bearings, Welds, …
    • Failure Analysis: useful learning tool
      • Care and handling of fractures
    • Repair techniques
      • Japan Air Lines 747 crash
    • “stop”-drill?
    • Helpful treatments and processes
      • plating
    • Hi-Tigue and other fatigue rated fasteners
    • Guidelines based on experience
  • Epilogue
  • No highway

 

"The strong point in the course was that we practiced how to apply fatigue concepts in dealing with practical applications."
 

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Courses:
Aircraft Structural Accidents | Fatigue, Fracture Mech, DTA | Corrosion of Aircraft Structures
Composite Structures | Aircraft Composites | A/C Structural Repair Analysis
 Advanced Damage Tolerance Analysis | Aging Aircraft Course

Typical duration of class is four days,
though longer and shorter versions are possible using the same syllabus.
This syllabus is for guidance only; the syllabus may change retaining the current flavor.

sam at fatcon dot com

Tel: 1 (916) 933 5000

 

Fatigue Concepts
300 Salmon Falls Road, El Dorado Hills, CA 95762  USA
FAX: +1 (916) 933-5222


Email Us!
sam@fatcon.com