水环境对热塑性复合材料层合板分层疲劳裂纹扩展的影响

本文研究了水环境对ICIAPC-2热塑性预浸料(AS4/PEEK)制成的单向复合材料层合板分层疲劳裂纹扩展的影响.用双悬臂梁试件进行了I型张开位移加载试验.试验环境为23℃水中和50℃水中.水环境未引起很大的不利影响.用电子显微镜和机理分析讨论了水环境对CF/PEEK和CF/环氧两种层合板的差异.

EFFECT OF WATER ENVIRONMENT ON PROPAGATION OF DELAMINATION FATGUE CRACK IN THERMOPLASTIC COMPOSITE LAMINATES

The effect of water environment on the growth of delamihation fatigue cracks was investigated with unidirectional laminates' made from ICI APC-2 thermoplastic prepregs (AS4/PEEK).Tests were carried out under mode I opening loading by using double cantilever beam specimens.the testing environment was water at 23℃ and 50℃.Moisture conditioned specimens were also tested in water at 23℃,The water envirnoment did not induce large detrimental effects.The crack growth rate was expressed as two power functions of the equivalent stress intensity range.The exponent of the power functions in the low growth rate region was smaller than that in the high growth rate region.lowering the frequency of stress cycling yielded accelerated crack growth in water,suggesting the time-dependent mechanism of crack growth.The difference of the enviromental effects between CF/PEEK and CF/epoxy laminates was discussed on the basis of the fractographic observation and mechanism consideration.