Evaluation of Shear Strength of Metallic Bonding According to the von Mises Yield Condition

摘要

The evaluation method of shear adhesive strength area was studied by biaxial testing machine for the cruciform adhesive joint with rectangular bonded area in comparison with that with circular bonded area. Stress distribution in the adhesive layer of the cruciform adhesive joint was analyzed by the finite element method (FEM). It was estimated that the von Mises equivalent stress was not influenced by the normal stresses influenced mainly by the shear stress. Fracture strength measurements were performed by the biaxial testing machine using the cruciform adhesive joints with rectangular bonded area. It was observed that the fracture strength of the cruciform joint with the adhesive that follows the Mises yield criterion (epoxide) was approximately constant, not depending on the loading ratio, as expected from FEM results. This suggested that the joint broke when the equivalent stress was applied in plastic region of the adhesive. On the other hand, the fracture strength of the joint with the adhesive that does not follow the Mises yield criterion (acrylic) was not constant. From these results it was concluded that this evaluation method could be useful for the estimation of changing tendency of adhesive bonded strength in the various loading ratio.