无方向数据采集的相控阵结构健康监测研究

Non-Directional Data Acquisition for Phased Array Based Structural Health Monitoring

超声相控阵结构健康监测过程中由于按角度扫描的数据采集持续时间长,结构损伤前后采集的数据易受环境和结构变化的影响,针对这一问题,提出无方向数据采集的相控阵结构健康监测成像定位方法。基于相控阵方法,对采集后数据根据发射和接收过程进行时间延迟的计算,然后将监测结果进行二维成像。该方法在玻璃纤维复合材料板结构上的实验研究证明,采用无方向数据采集的相控阵结构健康监测方法能够精确监测结构中损伤并对损伤进行清晰成像;并且该方法可以大大缩短监测时间,从而使监测过程不受环境条件变化的影响,为超声相控阵监测方法的工程化奠定基础。

Data acquisition for phased array based structural health monitoring is conducted according to direction in the certain scanning rang of the structure,which affects data acquisition easily by some external factors,such as,environment and the change of the environment and structure.Therefore,the non direction data acquisition for phased array damage identification imaging method is proposed.The same excitation signal is used for all sensors to generate the signals travelling in the structure.The health signals and the damage signals are obtained by the data acquisition method.The damage scattered signals are obtained by comparing the damage signals with the health signals.Based on the phased array theory,the time delay is added to the scattered signals in the signals emission process and the receiving process according to the direction and the sensors.The processed signals are drawn on 2-D mapped image.Experiment on the composite structure shows that the damage in the structure can be well recognized.The method utilizes non direction data acquisition.It can greatly shorten monitoring time and is not affected by the change of environment and structure.