エポキシ樹脂のき裂進展抵抗に与える準微視的構造因子の影響

概要

論文の詳細を見る
For the purpose of establishing an integrated explanation of fracture mechanism in the material, the authors have discussed several features of crack growth threshold in an epoxy resin which shows remarkable time-and temperature-dependent mechanical behaviors. Namely, using a wide strip specimen having a long (semi-infinite) crack perpendicular to the free edge, slow and stable crack growth behavior was carefully observed under a constant rate of displacement and several temperatures over the viscoelastic range of the material. Then a time-and temperature-independent crack growth resistance was successfully obtained from crack growth curves and an extended J-integral for a linearly viscoelastic material. Minute fracture surface roughness was measured quantitatively with a double-beam interference microscope. The characteristic feature of the fracture surface was seen in the neighborhood just ahead of the initial crack front. Taking the temperature and rate-dependent mobility of molecular entanglement around the moving crack front into account, some features of the submicroscopic mechanism of crack growth in this type of material are also discussed.
1993-04-25