| The impact behavior of the composite materials is paid more attention as an important phenomenon in military and civilian areas. In this current study, The air thermal cycling(-60~180?) and vacuum thermal cycling(-140~180?, 10-4Pa) were performed on the T700/HT280 composite. Meanwhile, the aging evolution and its damage mechanisms of CF/BMI composite exposed to different environment were investigated by using SEM ?microscope?C-scanning and DMA.The research results showed that after air thermal cycling and vacuum thermal cycling, the mass loss of T700 / HT280 composite and matrix resin were examined. It reveals that the mass loss rate all rises rapidly and then leveled off with increasing environment cycles.By comparing the tensile properties after the air thermal cycling and vacuum thermal cycling treatment, the tensile properties perform worse after two kinds of environment treatment.The air thermal cycling specimen bending properties changed little and inter-laminar shear properties became worse. But bending properties after vacuum thermal cycling became worse and inter-laminar shear properties were changed little. It suggests that the two kinds of environment researches on the aging mechanism of materials have obvious differenceTwo kinds of environmental treatment were different on the influence of the Tg. Tg has no obvious change after the air thermal cycling treatment. On the contrast, Tg increased obviously from 313? to 332? after the vacuum thermal cycling treatment.Low velocity impact test were measured after two kinds of environmental treatment. It reveals that the average impact damage size increases and the fracture mode varies with the increase of impact energy. And with the increasing of impact energy, impact energy also increases. But compared to the air thermal cycling, the air thermal cycling effect less influence on materials' impact properties. According to the calculation, the finite element could relatively well predict the low impact damage of composite. |
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