采用红外热像和声发射技术,实时同步监测2D C/SiC复合材料带孔板的拉-拉疲劳损伤过程,并利用疲劳过程中模量的变化、声发射信号和试样表面温度变化,讨论了带孔板疲劳损伤演变情况。结果表明:当外加应力低于疲劳极限时,疲劳损伤在循环初始阶段产生,损伤随循环数增加逐渐增大,最后趋于稳定;当外加应力超过疲劳极限时,疲劳损伤在短时间内迅速产生,直至试样断裂。声发射信号和温度变化与模量变化吻合较好,表明可以采用这些无损检测手段实时同步监测这种结构材料的疲劳损伤过程。
Infrared(IR) thermography and acoustic emission(AE) were employed to synchronously monitor damage evolution of center-holed 2D C/SiC composite plate under tensile-tensile fatigue loading.Damage evolution was discussed based on the modulus,the change of AE signal and surface temperature.When the applied stress is lower than the fatigue endurance limit,the major damage is initiated in the first few cycles and went steady as cycles proceeded.When the applied stress exceeds the fatigue endurance limit,mass damage engenders failure of composites.AE signals and temperature variations are in good agreement with the variation of modulus.It can be concluded that it is possible to employ these non-destructive evaluation methods as in-situ damage evolution indicator for 2D C/SiC composites under fatigue loading.