ガラスロービングクロス強化熱硬化性および熱可塑性樹脂複合材料のAE特性と破壊機構

抄録

In this paper, failure mechanisms and material assessing of thermoplastic matrix composite (glass cloth reinforced nylon-6, GFRN6) and thermoset matrix composite (glass cloth reinforced unsaturated polyester resin, GFRUP) were studied by using acoustic emission (AE) monitoring. GFRN6 was made under two different pressures of matrix impregnation. The effect of pressure on AE characteristics was also studied. The uniaxial tensile, unloading-reloading, loading-2 minutes holding and loading-30 minutes holding tests were carried out on those materials. During each test the load and AE parameters were recorded. Several AE parameters obtained during the uniaxial tensile tests indicated that the failure process of GFRUP consisted of (1) debonding between fiber and matrix, (2) matrix cracking, and (3) fiber breaking, while that of GFRN6 consisted of (1) debonding between fiber and matrix or the delamination of weft and warp and (2) fiber breaking. This means that no matrix cracking occurred in GFRN6. It became clear that the quality of impregnation of the thermoplastic matrix could be evaluated by the analyses of AE parameters. It was also shown that the Felicity ratio was a good indicator of the quality of impregnation. The ratio of the cumulative AE event counts over each holding interval to the total AE event counts during loading-holding testing was shown to be an indicator to evaluate the quality of adhesion between fiber and matrix. The AE events occuring during the load holding tests of GFRN6 and GFRUP were due to the debonding between fiber and matrix.