摘要
就湿热(70℃,相对湿度RH100％)环境对T300/914C石墨/环氧单向复合材料层板层间断裂韧性的影响进行了研究。用扫描电镜对断口形貌进行观察,不论是湿热处理的或是室温放置和经干燥处理的,断口形貌无明显差异。我们还对上述DCB试样在交变载荷作用下裂纹的扩展行为进行了研究。找出了裂纹扩展速率da/dN与最大循环应变能释放率G_(Imax)关系式da/dN=A·G_(Imax)~B中的A和B两个常数的数值。经湿热处理的DCB试样疲劳裂纹扩展速率与干燥试样相比有所降低。我们分别用断口形貌、断裂机理和断裂力学原理分析了湿热环境对复合材料性能的影响。
The heat-moisture effect on interlaminar fracture toughness of T300/914C graphite/e-poxy unidirectional composite laminates is investigated under mode I opening loading with DCB specimen. The fracture toughness in moisture-heat conditioning increases and the glass transition temperature decreases. SEM fractographs revealed no discernible difference in the fracture surface mophlogy of moisture-heat and dry conditioned specimen. No fiber bridging occurs in the testing.Delamination fatigue crack growth experiments are carried out on T300/914C graphite/ epoxy unidirectional laminates. It is found that the mode 1 cyclic crack growth rate yields a power low relationship between da/dN and the maximum cyclic strain energy release rate. The crack growth rate of the moisture-heat conditioned specimen is lower than the dry conditioned. The environmental effects are explained on the basis of fractography and fracture mechanisms and fracture mechanics.
出处
《北京航空航天大学学报》
EI
CAS
CSCD
北大核心
1993年第2期7-15,共9页
Journal of Beijing University of Aeronautics and Astronautics
关键词
石墨
环氧
复合材料
断裂韧性
graphite ,epoxy composite .fracture toughness,moisture heat,effect.
