论文部分内容阅读
针对飞机金属螺栓连接结构疲劳裂纹实时监测的需求,提出了一种基于柔性平面涡流阵列传感器的飞机金属结构疲劳裂纹监测方案,通过半解析建模对传感器的工作特性进行了研究,搭建了监测系统并通过试验对方案可行性进行了验证.半解析模型结果表明传感器感应通道与激励通道的相位差和幅值比随提离距离及被测试件电导率的变化曲线具有单调性,且幅值比变化大,敏感度高.程序载荷谱作用下2A12-T4铝合金试件疲劳裂纹监测试验结果表明:将各通道幅值比变化曲线中的拐点作为特征点,传感器通道1能对累积损伤进行监测,通道2,3,4能对疲劳裂纹扩展长度进行定量监测,监测精度达到1 mm.所提出的柔性平面涡流阵列传感器能够实现对疲劳试件从累积损伤到疲劳裂纹扩展整个寿命周期的监测.
Aiming at the requirement of real-time fatigue crack detection of aircraft metal bolted structure, a fatigue crack monitoring scheme of aircraft metal structure based on flexible planar eddy current array sensor is proposed. The working characteristic of the sensor is studied by semi-analytical modeling, and the monitoring system And the feasibility of the scheme was verified through experiments.The results of the semi-analytical model show that the phase difference and amplitude ratio of the sensor-induced channel to the excitation channel are monotonic with the distance of lift-off and the curve of the conductivity of the tested device, and the amplitude ratio Variations and high sensitivity.The test results of the fatigue crack of 2A12-T4 aluminum alloy specimen under the program load spectrum show that the inflexion point in the curve of amplitude ratio of each channel is taken as the characteristic point, and the sensor channel 1 can monitor the cumulative damage , Channel 2, 3, 4 can quantitatively monitor the fatigue crack propagation length and the monitoring accuracy reaches 1 mm.The proposed flexible planar eddy current array sensor can monitor the fatigue life of fatigue specimens from cumulative damage to fatigue crack growth.