Frontier Scientific Testing & Research has a industry-renowned reputation for dependable Fracture Toughness Testing.Our state-of-the-art Fracture Lab is designed for the high volume, quick turnaround projects demanded by the aerospace, automotive, power generation, and medical industries.

The most popular test performed in the Fracture Lab is the KIC Test per ASTM E399. Disc Shape, Arc Tension, Single Edge Bend and Compact Tension are all covered under the ASTM E399 specification. Our lab has the capability to handle specimens of many sizes.

Pre-cracking is an essential part of Fracture Toughness testing. The pre-crack is the creation of a simulated “flaw” that aids in the testing of fractured specimens. The actual crack, which initiates at the tip of a machined notch, is typically measured automatically using compliance techniques.

Fracture Toughness tests can be performed at various load capacities and temperatures.

Our servo machines can cover up to a 500,000 kg load. FST&R can also perform tests at temperatures ranging from Liquid Helium to cover 1300°C in both controlled and simulated atmospheres.

The K-R Curve testing per ASTM E561 can be performed on both compact specimens C(T) and center crack tension panels M(T). The K-R curve test provides valuable data about the toughness development as a crack is progressively propagated under an increasing applied stress intensity factor K. R-Curves and applied K-Curves are used to predict the critical stress intensity that will cause the onset of unstable fracturing.

Chevron Notch Short Rod and Short Bar testing per ASTM E1304 can be performed in the Fracture Mechanics Lab. The fracture toughness determined by this test shows the resistance of a material to fracture from a gradually advancing steady state crack utilizing a severe tensile constraint in a neutral environment. A KIV, KIVJ, or KIVM value may be assigned to estimate the correlation of failure and defect size.

Surface Crack Tension (SCT) testing, conducted to ASTM E740, estimates the load carrying capacity of sheet or plate components when a flaw has occurred. It is not uncommon for our Fracture Department to perform this test to cryogenic temperatures. The purpose of this test is to study the failure characteristics of cracks under simulated service conditions.

Additional Fracture Mechanics Testing Services:

•KIC

•Chevron Notch

•Short Rod

•Short Bar

•R-Curve Determinations

•Drop-Weight Tear Tests

•Nil Ductility Transition Temperature

•JIC

•CTOD

•Dynamic Tear Testing

•Notched Bar Impact (Charpy and Izod)

FST&R can provide the following Fracture Mechanics standard tests:

ASTM E399

ASTM E1820

ASTM E561

ASTM E740

ASTM E1304

ASTM E1681

ASTM E1820

ASTM E1921

ASTM E208

ASTM E604

The information on the following ASTM standard tests are provided “as is” without warranty of any kind. FST&R does not accept any responsibility or liability for the accuracy, content, completeness or the reliability of the information mentioned under each test. The information is partial and is taken from the current ASTM test listing at the time of publication. For complete and current test specifications and detail go to www.astm.org.

ASTM E399

Standard Test Method for Linear-Elastic Plane-Strain Fracture Toughness KIC of Metallic Materials

This test method covers the determination of fracture toughness (KIc) of metallic materials under predominantly linear-elastic, plane-strain conditions using fatigue pre-cracked specimens having a thickness of 1.6 mm (0.063 in.) or greater subjected to slowly, or in special (elective) cases rapidly, increasing crack-displacement force.

ASTM E1820

Standard Test Method for Measurement of Fracture Toughness

This test method covers procedures and guidelines for the determination of fracture toughness of metallic materials using the following parameters: K, J, and CTOD (δ). Toughness can be measured in the R-curve format or as a point value. The fracture toughness determined in accordance with this test method is for the opening mode (Mode I) of loading.

ASTM E561

Standard Test Method for K-R Curve Determination

This test method covers the determination of the resistance to fracture of metallic materials under Mode I loading at static rates using either of the following notched and pre-cracked specimens: the middle-cracked tension M(T) specimen or the compact tension C(T) specimen. A KR curve is a continuous record of toughness development (resistance to crack extension) in terms of KR plotted against crack extension in the specimen as a crack is driven under an increasing stress intensity factor, K.

ASTM E740

Standard Practice for Fracture Testing with Surface Crack Tension Specimens

This practice covers the design, preparation, and testing of surface-crack tension (SCT) specimens. It relates specifically to testing under continuously increasing force and excludes cyclic and sustained loadings. The quantity determined is the residual strength of a specimen having a semielliptical or circular-segment fatigue crack in one surface. This value depends on the crack dimensions and the specimen thickness as well as the characteristics of the material.

ASTM E1304

Standard Test Method Plane-Strain (Chevron-Notch) Fracture Toughness of Metallic Materials

This test method covers the determination of plane-strain (chevron-notch) fracture toughness, KIv or KIvM, of metallic materials. Fracture toughness by this method is relative to a slowly advancing steady state crack initiated at a chevron-shaped notch, and propagating in a chevron-shaped ligament. Some metallic materials, when tested by this method, exhibit a sporadic crack growth in which the crack front remains nearly stationary until a critical load is reached. The crack then becomes unstable and suddenly advances at high speed to the next arrest point. For these materials, this test method covers the determination of the plane-strain fracture toughness, KIvj or KIvM, relative to the crack at the points of instability.

ASTM E1681

Standard Test Method for Determining Threshold Stress Intensity Factor for Environment Assisted Cracking of Metallic Materials

This test method covers the determination of the environment-assisted cracking threshold stress intensity factor parameters, KIEAC and KEAC, for metallic materials from constant-force testing of fatigue pre-cracked beam or compact fracture specimens and from constant-displacement testing of fatigue pre-cracked bolt-load compact fracture specimens.

ASTM E1820

Standard Test Method for Measurement of Fracture Toughness

This test method covers procedures and guidelines for the determination of fracture toughness of metallic materials using the following parameters: K, J, and CTOD (δ). Toughness can be measured in the R-curve format or as a point value. The fracture toughness determined in accordance with this test method is for the opening mode (Mode I) of loading.

ASTM E1921

Standard Test Method for Determination of Reference Temperature, T, for Ferritic Steels in the Transition Range

This test method covers the determination of a reference temperature, To, which characterizes the fracture toughness of ferritic steels that experience onset of cleavage cracking at elastic, or elastic-plastic KJc instabilities, or both. The specific types of ferritic steels covered are those with yield strengths ranging from 275 to 825 MPa (40 to 120 ksi) and weld metals, after stress-relief annealing, that have 10 % or less strength mismatch relative to that of the base metal.

ASTM E208

Standard Test Method for Conducting Drop-Weight test to Determine Nil-Ductility Transition Temperature of Ferritic Steels

The ASTM E208 Drop-Weight Test is used primarily to determine the Nil-ductility transition temperature or NDT of ferritic steels of 5/8 in thickness and over. This particular drop weight test was initially developed by the Naval Research Laboratory in 1952 and published as Department of the Navy document NAVSHIPS-250-634-3.

ASTM E604

Standard Test Method for Dynamic Tear Testing of Metallic Materials

This test method covers the dynamic tear (DT) test using specimens that are 3/16 in. to 5/8 in. (5 mm to 16 mm) inclusive in thickness.