Damage Behavior of Adhesive Butt Joints Bonded with Rubber-Modified Epoxy
Akinori FUJINAMI, Katsuhiko OSAKA, Takehito FUKUDA and Makoto IMANAKA
Abstract:In the present study, damage behavior in the adhesive layer of adhesive butt joints bonded with rubber-modified epoxy was investigated by using an anisotropic damage theory. In the experiments, the stress-strain curves of the bulk specimens and the adhesive layer in the butt joints were measured by loading-unloading tests at a relatively low strain rate. The values of damage parameter D1 in the maximum principal stress direction were obtained from the measured stress-strain curves for the specimens. The relation between D1 and the strain energy density given to the specimens was investigated in order to compare the damage behavior of the butt joint and bulk specimens. From the results, it was found that the strain energy density of the specimens given until they break increased with rubber contents, but their damage behaviors were almost the same. It was also found that the strain energy densities of the specimens at their fracture were almost the same but the damage parameter D1 of the butt joint specimen was higher than that of the bulk specimen over the full range of strain energy. Key Words:Damage parameter, Anisotropic damage theory, Strain energy density, Maximum principal strain, Adhesive layer, Rubber-modified epoxy, Adhesive butt joint