Testing Company Now Offers Fracture Toughness Testing

Laboratory Testing Inc. (LTI) has added fracture toughness testing to its provided services. LTI’s fracture toughness test is performed on a specimen with a pre-existing crack to determine resistance to further crack extension. Fracture toughness testing measures the conditions under which an existing crack in a material will lengthen when under prescribed loading conditions. The company performs fracture toughness tests to American Society for Testing and Materials (ASTM) standards E399 and E1820. In design applications, fracture toughness is an important test because fractures are inevitable during manufacture. The test is also valuable in determining whether there is a danger of failure when a flaw is discovered in an existing structure.

LTI’s computerized fracture toughness test equipment can generate 55,000 pounds of tensile (material being stretched) or compressive (material being compressed) force. An environmental chamber controls the test temperature between -150° F and +350° F. The company offers various fixturing processes to test specimens in a range of sizes, such as single edge bend and compact tension.

Fracture toughness testing according to ASTM E399 applies a continuously increasing load to the specimen. ASTM E1820 uses a rising load with periodic partial unloading to measure the instantaneous crack length. Separate stress-intensity designations are used to characterize the fracture toughness of linear elastic materials, which are typically high strength materials that fail in a brittle manner, and elastic-plastic fracture toughness in more ductile materials that are better able to deform and resist crack growth under load.

Based in Hatfield, Pa., Laboratory Testing Inc. is an independent laboratory foundedin 1984. The company specializes in metals and plastics testing, material analysis, nondestructive testing, failure analysis, calibration, dimensional inspection, specimen machining and certified reporting of results.