湿热环境对复合材料疲劳性能的影响

Effect of hygrothermal environment on fatigue properties of composite materials

湿热环境对复合材料性能的影响可以归于对基体性能和界面性能影响的综合,一般湿热环境下材料性能会有所降低,但某些情况下湿热反而会使复合材料的力学性能提高。湿热环境下疲劳初始损伤出现较迟,最终破坏时纤维表面较为光滑,少有基体附着。实验对湿热疲劳试验过程中的环境、载荷、终止条件等几个部分进行讨论,其中试验件吸湿方法和湿热环境保证是进行湿热环境下疲劳试验需考虑的重点。对目前提出的3种疲劳寿命预测方法进行了对比,提出其一致的表达形式,并根据湿热环境对于复合材料疲劳寿命的影响规律,给出了该预测模型在湿热环境下的修正方法。

Influence of hygrothermal environment on the properties of composite materials can be attributed to the combination of influence on matrix and interfacial properties. Generally, the mechanicalproperties of composite material under hygrothermal environment will decrease,but in some cases, hygrothermal environment can even improve the mechanical properties of composite materials. The initial fatigue damage occurs later and the surface of fiber is more smooth and matrix adhering to fiber is less in hygrothermal environment. Several aspects of composite hygrothermal fatigue experiment like environment, load and termination conditionare discussed, In which moisture absorbing method and hygrothremal environment guarantee play an important role. Three prediction methods of fatigue life are compared, and a consistent expression form of these methods is given.Based onthe influence of hygrothermal environment on fatigue life of composite materials, the correction of predicting method under hygrothermal environment is given.