Leading experts provide 24 papers addressing four areas pertinent to fatigue crack growth thresholds: mechanisms, test procedures, analysis, and applications.Mechanisms: Three mechanisms that influence thresholds are discussed including: crack-tip closure, environment, and Kmax effects. A simplistic four-parameter model that describes FCG threshold behavior of elastic-plastic materials is also presented. Test Procedures: Eight papers focus on loading and specimen-type effects with research showing that the resistance-curve (R-curve) method to determine the threshold for fatigue-crack growth should allow more reliable application of ΔKth values to engineering problems. Analysis: Three papers analyze the behavior of fatigue cracks in the threshold regime using several different analysis methods. These methods were the elastic-plastic finite-element method (FEM), the Dugdale-type mode, the BCS (Bilby, Cottrell and Swinden) model, and a discrete-dislocation model. Applications: Nine papers address applications of threshold concepts and endurance limits to aerospace and structural materials. The impact of a number of testing variables on the measurement of fatigue-crack-growth thresholds, in particular ASTM E 647, Test Method for Measurement of Fatigue Crack Growth Rates is also discussed.
Mechanisms and Modeling of Near-Threshold Fatigue Crack Propagation
Henaff G., Petit J., Sarrazin-Baudoux C.
The Significance of the Intrinsic Threshold — What Is New?
Hadrboletz A., Stickler R., Weiss B.
Effects of Kmax on Fatigue Crack Growth Threshold in Aluminum Alloys
Newman J., Piascik R., Riddell W.
Resistance Curves for the Threshold of Fatigue Crack Propagation in Particle Reinforced Aluminium Alloys
Pippan R., Powell P., Tabernig B.
An Indirect Technique for Determining Closure-Free Fatigue Crack Growth Behavior
Piascik R., Smith S.
Effect of an Overload on the Threshold Level of Ti-6-22-22
DeCarmine A., McEvily A., Ohashi M., Shover R.
A Size Effect on the Fatigue Crack Growth Rate Threshold of Alloy 718
Garr K., Hresko G.
Effect of Geometry and Load History on Fatigue Crack Growth in Ti-62222
Liknes H., Stephens R.
The Mechanics of Moderately Stressed Cracks
Pippan R., Riemelmoser F.
Pitfalls to Avoid in Threshold Testing and its Interpretation
Bucci R., Bush R., Donald J.
Use of Small Fatigue Crack Growth Analysis in Predicting the S-N Response of Cast Aluminum Alloys
Allison J., Caton M., Jones J.
Prediction of Fatigue Limits of Engineering Components Containing Small Defects
Akiniwa Y., Tanaka K.
Mean Stress and Environmental Effects on Near-Threshold Fatigue Crack Propagation on a Ti6246 Alloy at Room Temperature and 500°C
Chabanne Y., Petit J., Sarrazin-Baudoux C.
Component Design: The Interface Between Threshold and Endurance Limit
Taylor D., Wang G.
Near-Threshold Fatigue Strength of a Welded Steel Bridge Detail
Albrecht P., Wright W.
Fatigue Crack Growth Thresholds Measurements in Structural Materials
Lidar P., Lindström R., Rosborg B.
Endurance Limit Design of Spheroidal Graphite Cast Iron Components Based on Natural Defects
Marquis G., Rabb R., Siivonen L.
Paper ID: STP1372-EB