【作者】 张含琦； 吴奇； 王容； 熊克； 宫晨；

【Author】 ZHANG Hanqi;WU Qi;WANG Rong;XIONG Ke;GONG Chen;State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics;

【机构】 南京航空航天大学机械结构力学及控制国家重点实验室；

【摘要】 航空复合材料结构如碳纤维桨叶在服役过程中受到的冲击损伤严重威胁航空安全,因此需要进行超声结构健康监测。然而,碳纤维桨叶因其各向异性材料、层叠结构和复杂构造,存在传感器贴附困难、超声衰减严重和超声模式复杂等问题。为解决上述挑战,本文搭建了基于相移光纤光栅的声-超声探测系统,成功监测了碳纤维桨叶的目视几乎不可见冲击损伤。光纤传感系统具有探头微小、柔性、灵敏度高等优点。通过分析超声信号波形,发现激励信号周期为5、频率为50 kHz时,信号幅值、到达时间差和相关性与冲击损伤的个数都存在线性关系。结果表明,本文搭建的相移光纤光栅超声平衡探测系统可以应用于航空复合材料复杂结构的声-超声探伤,并且对超声信号进行类兰姆波的数据处理可以评估桨叶的冲击损伤。更多还原

【Abstract】 Structural health monitoring(SHM) of the carbon fiber propeller is necessary because the impact damage seriously threatens aviation safety. However, the complex structure of a carbon fiber propeller induces multiple problems including sensor installation, ultrasonic attenuation, and complex mode of the ultrasonic guided wave. An acousto-ultrasonic detection system based on phase-shifted fiber Bragg grating(PSFBG) was set up to monitor the barely visible impact damage of the carbon fiber propeller. The optical fiber sensing system is small,flexible, and highly sensitive, therefore, suitable for the carbon fiber propeller. It was found that the amplitude,arrival time, and correlation of the ultrasonic waves varied linearly with the number of impact damage given the input ultrasonic wave had a central frequency of 50 kHz. The results suggest that the PSFBG balanced sensing system can be applied to the acousto-ultrasonic detection of carbon fiber propeller, and data processing that was analogous to the analysis method of Lamb wave can be used to evaluate the impact damage of carbon fiber propeller.更多还原