Analysis of impact fracture in adhesive block joints

Abstract

The article presents the results of the analysis of the damage type and the regularity of adhesive joints impact fracture. The experimental testing was conducted with a pendulum hammer designed to examine adhesive joints. Tests of block samples were carried out according to the Standard ISO 9653. The maximum energy of the pendulum used in the investigation equalled 15 J. In order to determine the impact strength of the examined connections, we used a dependency according to which the energy used to detach the upper element of the sample in such a test, that is the energy lost by the pendulum, is the measure of impact strength of the adhesive joint. The adherends were made of steel S235 or an aluminum alloy 2017A. In order to bond the samples, we used Epidian 57 epoxide resin with Z1 hardener or Loctite 3421 adhesive. The results of the experimental investigation indicate that adhesive joints made of both of the tested adhesives are characterized by cohesive-adhesive damage. Placed in joints spacers of the sewing threads form do not affect the impact strength of the tested adhesive joints. Macroscopic analysis of low-thickness joints does not make it possible to conclude clearly about the nature of joint fracture.

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