This test method provides a means of measuring the cleavage forces and energies required to fail adhesively bonded reinforced flat bonded specimens. It also offers a semi-quantitative observation of failure mode.

This test method has found application in screening structural adhesives for bonding reinforced plastics where simple lap shear testing has proven to be inadequate in distinguishing differences between adhesives.

It is important to note that the test method measures performance properties of the total bonded system (for example, reinforced plastic and adhesive) but will not yield fundamental properties of the adhesive alone.

1.1 This test method covers the determination of fracture strength in cleavage of adhesive bonds when tested on standard reinforced plastic specimens and under specified conditions of preparation and testing (Note 1).

Note 1—While this test method is intended for use in reinforced plastic applications, it may be used for measuring fracture properties of adhesives using other plastic adherends, provided consideration is given to the thickness and should be of equal rigidity to the plastic adherends.

1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.