摘要
针对稀疏阵列损伤定位精度低和分辨率不高的问题,基于超声导波频散和多模态效应,提出了一种适用于薄壁结构损伤识别的相控阵超声导波多模态融合成像方法。首先,利用频散预补偿机制构造超声导波频散预补偿激励信号,消除超声导波响应信号的频散效应,校正相位失真,实现超声导波合成波阵面动态聚焦;其次,通过Chirp线性调频信号激励技术,提取A0模态和S0模态占优的窄带高频超声导波响应信号作为检测波形,利用相控阵全聚焦方法构造单模态超声导波全聚焦成像;最后,利用不同模态超声导波频散特性差异显著的特点,融合A0模态和S0模态相控阵超声导波全聚焦成像结果,实现超声导波多模态融合成像。实验结果表明:所提超声导波多模态融合成像方法不需要基准信号,能够实现铝板结构单损伤、多损伤高精度定位和高分辨率成像,最大定位误差仅为7.2 mm;相比于单模态聚焦成像,多模态融合成像结果可以有效提高损伤成像的分辨率和信噪比,抑制旁瓣,避免产生伪像。所提方法可为薄壁结构多损伤检测提供有效途径。
Aiming at the existing problems such as low positioning accuracy and poor imaging resolution for damage detection of sparse array,a guided wave multi-mode fusion imaging method was proposed for damage detection of thin-walled structures based on the dispersion and multi-mode effects of guided wave.Firstly,the dispersion pre-compensation mechanism was adopted to construct excitation signal with dispersion pre-compensation to eliminate dispersion effect of ultrasonic guided wave response signal and correct phase distortion.In this way,the synthesis wavefront of guided wave signal achieved dynamic focusing.Secondly,the narrowband high frequency guided wave response signal dominated by A0 mode and S0 mode was extracted as detection waveforms by Chirp linear frequency modulated excitation signal.And the total focusing method was employed to establish the single mode total focusing imaging of guided by those detection waveforms,respectively.Finally,the significant difference in dispersion characteristics of guided wave for different modes were utilized to achieve guided wave multi-mode fusion imaging by fusion of various total focusing imaging results from A0 mode and S0 mode guided wave.The results show that the proposed guided wave multi-mode fusion imaging method achieves high precision positioning and high resolution imaging for both single and multiple damage detection of aluminum plate without baseline signals.And the maximum positioning error is 7.2 mm for multiple damage detection.In conclusion,the proposed multi-mode fusion imaging method can effectively improve the resolution and signal-to-noise ratio of damage imaging,suppress side lobe and avoid artifacts compared with single-mode focusing imaging.The proposed method can provide an effective way for multiple damage detection of thin-walled structures.
作者
左浩
邢娇
康敬东
惠记庄
ZUO Hao;XING Jiao;KANG Jingdong;HUI Jizhuang(School of Construction and Machinery,Chang’an University,Xi’an 710064,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2023年第4期88-96,共9页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(51905041)
中国博士后科学基金资助项目(2022M720531)
中央高校基本科研业务费专项资金资助项目(300102252202)。
关键词
薄壁结构
损伤识别
超声导波
频散补偿
多模态融合成像
thin-walled structures
damage detection
guided wave
dispersion compensation
multi-mode fusion imaging
