Scope:

The standard test method, Translaminar Fracture Toughness of Polymers ASTM E1922, is used to determine the parameter K_TL under opening mode loading, which is a measure of a polymer matrix composite laminate’s resistance to notch-tip damage and effective translaminar crack propagation. K_TL data is used to set material processing, component inspection criteria, test speed, and temperature. K_TL data also determines the effects of fiber and matrix factors and the laminate stacking sequence on the specimen.

Procedure:

In the ASTM E1922 test, the specimen length is measured to the nearest 0.1 mm, thickness to 0.002 W, and width to 0.05 mm. Then the specimen is loaded at a pace that takes between 30 and 100 seconds from zero to peak load. Finally, a plot is made with a 0.7 to 1.5 plotting scale of load versus displacement. The test is repeated until the shipment reaches 50% of its maximum value.

Specimen size

For ASTM E1922 testing, the specimen width should be 0.015 W, and the length of the notch should be between 0.5 and 0.6 times the specimen width W.

Data:

K = [P/BW^1/2]α^1/2 [1.4+α][3.97 – 10.88 α + 26.25 α² – 38.9 α³ + 130.15 α⁴ – 9.27 α⁵]/[1 – α ]^3/2

where:
K = applied stress intensity factor,
P is the load,
α = a/W (dimensionless),
B is the specimen thickness,
W is specimen width.

Conclusion:

The standard test method, Translaminar Fracture Toughness of Polymers ASTM E1922, is used to determine the parameter K_TL under opening mode loading, which is a measure of a polymer matrix composite laminate’s resistance to notch-tip damage and effective translaminar crack propagation.