金属内部裂纹的超声衰减特性与近表面缺陷识别

基金项目:

“十二五”国家科技支撑计划资助项目（2012BAF04B02）；国家自然科学基金青年科学基金资助项目（51304019）

详细信息

Ultrasonic attenuation characteristics of metal materials with cracks and identification of subsurface flaws

1. National Engineering Research Center of Flat Rolling Equipment, University of Science and Technology Beijing, Beijing 100083, China;
2. School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China

摘要: 建立了包含裂纹缺陷的二维金属板模型.采用有限元方法，对具有不同深度裂纹的材料内部超声波场进行计算，获得了不同裂纹深度金属材料上表面的回波信号，分析了裂纹深度对超声波传播特性的影响规律.进一步分离提取不同阶次底面回波的频谱特征，获得了由裂纹缺陷引起的超声衰减系数随频率的变化关系.最后提出了通过底面回波频谱图辨识近表面裂纹缺陷的方法.
- 近表面 /
- 裂纹 /
- 无损检测 /
- 超声 /
- 衰减 /
- 辨识
Abstract: A two-dimensional isotropic plate model with an embedded horizontal crack was established. Finite element analysis with absorbing boundary condition was employed to simulate the experimental pulse-echo mode to obtain ultrasonic data. The effect of crack depth on the wave propagation was studied and the spectra of different backwall echoes were further extracted. A relationship was determined between ultrasonic attenuation due to the crack and frequency. Finally, a method was proposed for identifying subsurface cracks based on the spectra of backwall echoes.
- subsurface /
- cracks /
- non-destructive testing /
- ultrasonic /
- attenuation /
- identification