LAUSR

Abstract This paper presents a modified pendulum hammer adapted to test the impact strength of lap joints. The impact tests of lap specimens exhibited greater repeatability in terms of the results, compared with the tests of block specimens (specimens used in Block Shear Test (ISO 9653)). The modified testing device also allowed for testing of rivet and hybrid rivet–adhesive joints. The comparative tests showed that the impact strength of the hybrid connections was greater than the sum of the impact strengths of the adhesive and rivet joints. Our research demonstrated the significant effect of the impact speed on the measured impact strength; this effect appeared to be related to the deformation energies of the test device and connected elements, which were more deformed at a lower load speed. We also showed a serious influence of adhesive forces on the impact strength of glued joints.