MECHANICAL TESTING

Fracture Toughness of Metals – ASTM E1820 (elastic/plastic)

The ASTM E1820 test determines the fracture toughness of metals using the parameters of K, J, and Crack-Tip Opening Displacement (CTOD). The fracture toughness is calculated by taking a fatigue, pre-cracked specimen with a notch and using a double cantilever to push the two sides of the notch away from each other. This allows our technicians to observe how the sample splits. There are three possibilities of how the specimen could split: fracture instability which results in a single point-value of fracture toughness, stable tearing which results in an R-curve, and stable tearing interrupted by fracture instability which results in an R-curve that ends at the point of instability. These values could be used for material comparison by yield strength, selection, and quality assurance. They could also help set a standard for structural flaw assessment.

Reference: Standard Test Method for Measurement of Fracture Toughness – ASTM E1820

Index of Mechanical Testing