... data has been generated from threshold to near fracture using the compression precracking constant amplitude or compression precracking load reduction test methods in the threshold regime; and constant-amplitude loading at higher rates. A remote back-face strain (BFS) gage was used to monitor crack...

... in the threshold regime at high load ratios were attributed to K max effects. But recent measurements of crack-closure behavior under high R and constant K max test conditions near threshold conditions on a variety of materials have indicated that these tests may not be crack-closure free as suspected. Strain...

.... Therefore, the threshold of fatigue crack growth of brazed joints is of particular importance in the fatigue analysis of brazed components and needs to be understood well. Residual stresses have to be considered in crack growth analysis in the threshold regime. The corresponding effects are explored...

...John J. Ruschau; James C. Newman, Jr. The scope of this paper is to determine the fatigue-crack growth rates in the near-threshold regime for both an aluminum and titanium alloy using the compression precracking constant-amplitude (CPCA) test method on compact specimens. Tests were conducted over...

... Metal 617, Haynes® 230, Haynes 214, Hastelloy X, 310 stainless steel, alonized Haynes 230, 304 stainless steel, and alonized Incoloy 800 HT. KEYWORDS: oxygen, ignition, temperature, WSTF, burning, rods, ammability, static, threshold, heated promoted combustion Introduction Many components are used...

... that gave rise to an increased risk of failure. The material used in constructing the valve, Haynes 25, possesses good long crack threshold fatigue properties ( Δ K th = 4.5 MPa m ). However, continued operation of the valves produced cracking under certain physiological circumstances. These assessments...

...MA James; SC Forth; JA Newman Compression precracking (CPC) has seen renewed interest as a possible alternative procedure for generating fatigue crack growth threshold data with minimal load history effects, but recent testing confirms results from the literature that compression precracking does...

...SR Daniewicz Three-dimensional elastic-plastic finite element analyses were conducted to model fatigue crack growth in an M(T) specimen. Variable amplitude loading with a continual load reduction was used to simulate the load history associated with fatigue crack growth threshold measurement. Load...

...SC Forth; JC Newman, Jr; RG Forman The accurate representation of fatigue crack threshold, the region defining crack growth as either very slow or nonexistent, is extremely important. If the experimentally measured threshold is unconservatively high, a structural component designed with this data...

...PJ Golden; T Nicholas The objective of this research was to measure the load history effects of negative stress ratio loading on the high cycle fatigue (HCF) crack growth threshold of Ti-6Al-4V. Previous work has shown an increase in the HCF threshold that is dependent on the K max during the low...