固体状ゴム粒子変成エポキシ樹脂接着剤層中のき裂の破壊敵性値とき裂先端ひずみ分布に対する接着剤層厚さの影響

摘要

The fracture behavior of a crack in an adhesive joint is important to investigate the integrity of adhesive structures. It is well known that the fracture toughness of a crack in an adhesive joint using ductile adhesive depends on the bond thickness. However, the mechanism of the dependence has not yet been elucidated. In the present study, we measured the fracture toughness of adhesive joints consisted of aluminum and rubber modified epoxy resin under mode I loading. The distributions of strain around a crack tip were measured using a micro-video-scope and the digital image correlation method (DICM). The measured distributions of strains were compared with that estimated using the finite element method (FEM) in conjunction with Gurson's model. The fracture toughness of adhesive joints used in this study decreased with the decrease of the bond thickness. According to the measurement and analyses, it is estimated that the stress and damage around a crack tip in a thinner adhesive layer were more increased by the higher constraint effect of adherends.%接着継手は航空機や工業用構造物に幅広く使われrnているが，接着剤層中に存在するき裂の破壊強度が接rn着構造物の信頼性に大きな影響を及ぼす．接着剤層厚rnさは，接着構造物の重要な設計パラメータの一つであrnり，接着継手の破壊靭性値に及ぼす影響について様々rnな研究が行われている．