混合モード荷重下における高じん性化エポキシ系接着剤の静的および疲労き裂進展特性

抄録

Static and fatigue crack propagation properties of epoxy adhesives under Mode I, Mode II and their Mixed Mode loading were investigated. Three types of specimens were used to examine the effect of the mixed mode ratio on the static and fatigue criteria ; Double cantilever beam (DCB) for Mode I, Tapered End Notched Flexure (TENF) for Mode II and Mixed Mode Bending (MMB) specimens. Two types of epoxy adhesives (unmodified and toughened with sub-micron rubber particles) were tested. The static test results revealed that the fracture toughness of unmodified and toughened epoxy adhesives (evaluated by the total energy release ratio G_t= G_I+ G_II) changed with respect to a mixed mode ratio (Mode I /Mode II). The fatigue test also revealed that the crack grows characteristics in the epoxy adhesives (such as a da/dN-ΔG_t, relation) also changed with respect to a mixed mode ratlo.