July 24, 2013
Laboratory Testing Inc. offers fatigue crack growth testing, also called da/dN testing, according to the ASTM E647 standard. Constant load; increasing, decreasing, and constant delta K; and constant Kmax control methods are offered. The test can be performed at temperatures from -250 to 400 degrees F at loads from 50 to 55,000 lbs.
The fatigue crack growth test generates a curve displaying the crack growth rate as the cyclic stress intensity factor (delta K) is varied. The test results also provide the data points and a da/dN-dK plot. Additionally, the company can provide customers with threshold and Paris law values, as well as adaptable testing for specific needs.
The fatigue crack growth test reports the resistance of materials to stable crack extension under cyclic loading. Compact tension (C(T)) and middle tension (M(T)) specimen configurations are supported in a variety of sizes. The M(T) specimen is used primarily for sheet materials, and the C(T) is used for such materials as sheet, plate, bar, and forgings.