Scope:

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

Procedure:

In the ASTM E1922 test, firstly specimen length is measured to nearest 0.1 mm, thickness to 0.002 W, 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

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

Data:

K = [P/BW1/2]α1/2 [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 load, α = a/W (dimensionless), B is specimen thickness, W is specimen width.