New impact specimen for adhesives: optimization of high-speed-loaded adhesive joints

A new kind of joint specimen has been developed to load the adhesive in pure shear on impact. The specimen is tested with three adhesives at five layer thicknesses, and at three test speeds. From these tests it can be concluded that the rod-ring specimen is suitable for use in impact tests at high speeds and for comparing impact tests with static tests. Owing to lateral contraction the specimen does not give the desired pure shear. Increasing the load speed causes an increase in energy absorption. A tough adhesive shows a larger energy absorption at impact than a brittle adhesive. There are optimum adhesive thicknesses at different test speeds. These thicknesses depend both on the adhesive used and on the test speed.