ASTM E3039 Determination of Crack-Tip-Opening Angle

Scope:

The standard test method, Determination of Crack-Tip-Opening Angle ASTM E3039, is used to estimate the critical steady-state crack-tip opening angle (CTOA) using measurements of force (P) versus load-line displacement, using the simplified single-specimen method (S-SSM). CTOA’s critical value is used to characterize the stable tearing in thin metallic materials as a fracture resistance criterion. ASTM E3039 is used as a pipe mill test to measure fracture propagation resistance.

Procedure:

According to ASTM E3039, the force versus displacement of a test specimen is recorded when it is completely cracked. Firstly, the specimen is immersed in a suitable solvent, and the temperature is maintained at -73°C to 100°C. Finally, the object is placed in the testing machine so that the notch in the specimen is within 1.59 mm (1/16 in.) of the striker’s centerline.

Specimen size

W = 76 mm and L = 305 mm is the width and length requirements for the specimen.

Data:

The following calculation is done in ASTM E3039 testing:

CTOAb/2= 8rp180
where:
rp= the rotation factor, ξ is the absolute value of the slope, and CTOA is in units of degrees.

Conclusion:

The standard test method, Determination of Crack-Tip-Opening Angle ASTM E3039, is used to estimate the critical steady-state crack-tip opening angle (CTOA) using measurements of force (P) versus load-line displacement, using the simplified single-specimen method (S-SSM).