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AFGROW
Fracture Mechanics and Fatigue Crack Growth Analysis software tool
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Download AFGROW Version 4.0012.15
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Sections
1. Introduction
0. Introduction
1. Historical Perspective on Structural Integrity in the USAF
2. Overview of MIL-HDBK-1530 ASIP Guidance
3. Summary of Damage Tolerance Design Guidelines
0. Summary of Damage Tolerance Design Guidelines
1. Summary of Guidelines
2. Design Category
3. Inspection Categories and Inspection Intervals
4. Initial Damage Assumptions
0. Initial Damage Assumptions
1. Intact Structure Primary Damage Assumption
2. Continuing Damage
3. Fastener Policy
4. In-Service Inspection Damage Assumptions
5. Demonstration of Initial Flaw Sizes Smaller Than Those Specified
5. Residual Strength Guidelines
0. Residual Strength Guidelines
1. Fail-Safe Structure at Time of Load Path Failure
2. Determining the Residual Strength Load for Remaining Structure
6. Required Periods Of Safe Damage Growth
0. Required Periods Of Safe Damage Growth
1. Slow Crack Growth Structure
2. Fail Safe Multiple Load Path Structure
3. Fail Safe Crack Arrest Structures
7. Illustrative Example Of Guidelines
0. Illustrative Example Of Guidelines
2. Fail Safe Structure
0. Fail Safe Structure
1. In-Service Inspection Consideration
2. Initial Flaw Considerations
3. In-Service Flaw Assumptions Following Inspection
4. Adjacent Structure Damage Following the Failure of the Major Load Path
5. Analysis of Intact Structure–Residual Strength Guidelines and Damage Growth Limits
6. Analysis of Intact Structure (Alternate Requirement)
7. Discussion of Intact Structure Analysis
8. Analysis of Remaining Structure Subsequent to Load Path Failure
9. Derivation of Residual Strength Load
10. Incremental Damage Growth Da
11. Alternative-Analysis of Remaining Structure Subsequent to Load Path Failure
12. Summary and Comments
4. Sustainment/Aging Aircraft
0. Sustainment/Aging Aircraft
1. Widespread Fatigue Damage
2. The Effect of Environment and Corrosion
5. References
2. Fundamentals of Damage Tolerance
0. Fundamentals of Damage Tolerance
2. Fracture Mechanics Fundamentals
0. Fracture Mechanics Fundamentals
1. Stress Intensity Factor – What It Is
2. Application to Fracture
3. Fracture Toughness - A Material Property
4. Crack Tip Plastic Zone Size
5. Application to Sub-critical Crack Growth
6. Alternate Fracture Mechanics Analysis Methods
0. Alternate Fracture Mechanics Analysis Methods
1. Strain Energy Release Rate
0. Strain Energy Release Rate
1. The Griffith-Irwin Energy Balance
2. The Relationship between G, Compliance, and Elastic Strain Energy
2. The J-Integral
0. The J-Integral
1. J-Integral Calculations
2. Engineering Estimates of J
3. Crack Opening Displacement
3. Residual Strength Methodology
5. Deterministic Versus Proabilistic Approaches
6. Computer Codes
0. Computer Codes
1. Structural Analysis
3. PRobability Of Fracture (PROF)
7. Achieving Confidence in Life Prediction Methodology
8. References
3. Damage Size Characterizations
0. Damage Size Characterizations
2. Equivalent Initial Quality
0. Equivalent Initial Quality
1. Description of Equivalent Initial Quality Method
2. Example Application of Equivalent Initial Quality Method
3. Proof Test Determinations
0. Proof Test Determinations
1. Description of the Proof Test Method
2. Examples
4. References
4. Residual Strength
0. Residual Strength
1. Introduction
0. Introduction
1. Slow Crack Growth Structure
2. Fail-Safe Structure
2. Failure Criteria
0. Failure Criteria
1. Ultimate Strength
2. Fracture Toughness - Abrupt Fracture
3. Residual Strength Capability
0. Residual Strength Capability
1. Single Load Path Residual Strength Diagrams
2. Built-Up Structure Residual Strength Diagrams
4. Single Load Path Structure
0. Single Load Path Structure
1. Abrupt Fracture
2. Tearing Fracture
5. Built-Up Structures
0. Built-Up Structures
1. Edge Stiffened Panel with a Central Crack
2. Centrally and Edge Stiffened Panel with a Central Crack
3. Analytical Methods
4. Stiffener Failure
5. Fastener Failure
6. Methodology Basis for Stiffened Panel Example Problem
7. Tearing Failure Analysis
8. Summary
6. References
5. Analysis Of Damage Growth
0. Analysis Of Damage Growth
2. Variable-Amplitude Loading
0. Variable-Amplitude Loading
2. Integration Routines
3. Cycle-by-Cycle Analysis
3. Small Crack Behavior
5. Crack Growth Prediction
0. Crack Growth Prediction
1. Cycle Definition and Sequencing
2. Clipping
3. Truncation
4. Crack Shape
5. Interaction of Cracks
6. References
7. Damage Tolerance Testing
0. Damage Tolerance Testing
1. Introduction
2. Material Tests
0. Material Tests
2. Sub-Critical Crack Growth Testing Methods
0. Sub-Critical Crack Growth Testing Methods
1. Crack Growth Rate Testing
2. Stress Corrosion Cracking
3. Quality Control Testing
4. Analysis Verification Testing
0. Analysis Verification Testing
2. Residual Strength Methods-Verification
3. Crack Growth Modeling-Verification
5. Structural Hardware Tests
0. Structural Hardware Tests
1. Test Conditions
2. Initial and Continuing Damage
3. Residual Strength Testing
4. Damage Tolerance Test Articles
5. Evaluation and Interpretation of Test Results
6. References
9. Structural Repairs
0. Structural Repairs
1. Required Analysis
3. Spectrum Analysis for Repair
0. Spectrum Analysis for Repair
1. Definition of Stress Histories
2. Spectra Descriptions
0. Spectra Descriptions
1. Exceedance Curve Descriptions
2. RMS Descriptions
3. Crack Growth Analysis
0. Crack Growth Analysis
1. Generation of Crack Growth Curves
2. Analysis of Observed Behavior
3. Interpertation and Use of Crack Growth Rate Curves
4. Analysis for Multiple Stress Histories
4. Life Sensitivity for Stress Effects
5. Life Sensitivity Analysis for Hole Repair
6. Blend-Out Repairs
7. Residual Strength Parametric Analysis
8. References
10. Guidelines for Damage Tolerance Design and Fracture Control Planning
0. Guidelines for Damage Tolerance Design and Fracture Control Planning
1. Design Loads Spectrum
2. Material Selection
0. Material Selection
1. Crack Growth Resistance and Fracture Toughness
2. Material Property Control
3. Structural Configuration Analysis
0. Structural Configuration Analysis
1. Critical Parts List
2. Inspection Method Development
3. Demonstration Test Development
4. Manufacturing Process
0. Manufacturing Process
1. Review of manufacturing process and inspections
2. Development of Critical Parts Accountability
5. References
11. Summary of Stress Intensity Factor Information
0. Summary of Stress Intensity Factor Information
1. Background of Stress Intensity Factors
3. Selected Stress Intensity Factor Cases
5. Computer Codes
0. Computer Codes
1. NASGRO Fracture Analysis Software
2. AFGROW Fracture Analysis Software
3. Cracks2000 Structural Integrity Software
6. References
Examples
1. FAC Problems
0. Computing Stress Intensity Factor Histories
1. Predicting Residual Strength - Fuselage Section
2. Crack Interaction and Multi-Site Damage
3. Predicting Ductile Tearing and Residual Strength - Flat Sheet
2. Merc Problems
0. Crack Growth Prediction - Center Wing Component
1. Damage Tolerance Analysis - Windshield Doubler
2. Sensitivity of Crack Growth Rates to Operating Conditions
3. Influences of Retardation Models on Crack Growth Predictions
3. NRC Problems
0. Quantifying Corrosion in Lap Joints
1. Residual Life Assessment - Corroded Lap Joints
2. Effect of Discontinuity States on the Risk Assessment - Corroded Lap Joints
4. SIE Problems
0. Crack Growth Analysis - Main Cargo Door (MSD Cracks)
1. Damage Tolerance Analysis - Wing Main Spars
2. Crack Growth Analysis - Main Cargo Door (Primary and Continuing Damage)
3. Damage Tolerance Analysis - Rear Wing Spar
4. Crack Growth and Residual Strength Analyses - Lap Joint
5. UDRI Problems
0. Crack Growth Analysis - Front Wing Spar
1. Risk Assessment - Fail Safety of a Stringer
2. Risk Assessment - Multiple Element Damage
3. Risk Assessment - Corrosion in a Lap Joint
Blog
Related Links
USAF ASC Engineering Directorate
http://public.ascen.wpafb.af.mil
Air Force Research Lab
http://www.afrl.af.mil
University of Dayton Research Institute
http://www.udri.udayton.edu
Joint Service Specification Guides (JSSG)
The Joint Service Specification Guides
can be ordered from this site
http://public.ascen.wpafb.af.mil/engstds/jssg.asp
Wright-Patterson AFB Engineering Standards Office
The Wright-Paterson AFB Engineering Standards Office
provides its many DoD and industry customers with information and "tools" for the effective management of aeronautical requirements, verfications, tailoring guidance, and lessons learned.
http://public.ascen.wpafb.af.mil/engstds/engstds.asp
AFGROW: Air Force Fracture Mechanics Software
http://www.afgrow.net
Cracks 2000: Crack Growth Software
http://www.udri.udayton.edu/cracks/
NASGRO: Fracture Mechanics and Fatigue Crack Growth Analysis Software
http://www.nasgro.swri.org/
FRacture ANalysis Code 2-D/Layered
http://www.mne.ksu.edu/~franc2d/