Tensile adhesion tests have been used for many years as a quality control tool and to quantify the strength of a bond. The quantity generally reported as the tensile strength is the breaking force per unit bond area (average axial stress at the maximum load). The stress distribution in tensile adhesion tests, as discussed in this report, depends upon many factors such as material properties of the adherend and adhesive and the ratio of bond area to adhesive thickness. Test data are presented which demonstrate that the debond initiation point changes from the bond edge to the center of the bond area as the adhesive thickness is decreased. These test data confirm a prior prediction by the authors.

The stress distribution and debond load were shown to be very sensitive to test specimen alignment during the tensile test. A test grip has been designed and used to alleviate effects of specimen misalignment. The effect of the modified test grip on tensile adhesion tests is discussed. A very large decrease in data variability as well as a 76% gain in apparent load carrying capability were observed when the modified test grip was used with brittle epoxy tensile adhesion test specimens.