고무변성 에폭시 수지의 균열선단 손상역 발달과 음향 방출 특성

Abstract

A damage zone around a crack tip occurred before fracturing is a significant data, which offer the toughening mechanism of a materials. The growth processing of damage zone in the vicinity of crack tip for rubber-modified epoxy resin is investigated using an acoustic emission(AE) analysis system. The volume fractions of rubber(CTBN 1300×8) in rubber-modified epoxy resin are 5% and 15%. The fracture toughness(KIC) and the fracture energy(GIC) were measured using single notch 3 point bending specimens. The damage zone and rubber particles distributed around the crack tip of damaged specimens were observed by a polarization microscope and an atomic force microscope(AFM). The damage zone around crack tip of rubber-modified epoxy resin appears in 13.1% loading and develops into 57.2% loading based on 100 % fracture loading. The propagated-behavior of stable crack which initiated at 57.2% loading occurs in discontinuity. At the maximum loading, it has changed into unstable crack and the modified epoxy resin is broken