摘要
分析了导波在圆管中传播的模态,探讨了在圆管中激励纵向导波的磁致伸缩作用力模型。纵向导波由平行于圆管轴向的磁致伸缩力的作用而产生,磁致伸缩力除与被检测材料的特性有关外,主要取决于设置的静态偏置磁场和交变磁场的耦合作用。根据该模型设计了在圆管中激励纵向导波的磁致伸缩传感器,试验中获得了纵向导波,并通过磁致伸缩传感器对圆管分别作用不同的静态偏置磁场和交变磁场,试验研究两者对激励的纵向导波的影响。结果表明:作用于圆管上的静态偏置磁场与激励的纵向导波幅值呈抛物线关系,在低偏置磁场作用下,纵向导波幅值随着偏置磁场的增加而增大,在高偏置磁场作用下,纵向导波幅值随着偏置磁场的增加反而减小。导波在圆管中传播时,存在多模式和频散特性,交变磁场大小与激励的纵向导波幅值之间呈非线性关系。
The modes of guided wave propagation in the circular pipes are analyzed. The model of magnetostrictive force-generated longitudinal guided waves in circular pipes is discussed. The longitudinal guided waves are generated by application of magnetostrictive force parallel to the axial direction of circular pipes, and the magnetostrictive force not only relates with the characteristics of detected materials, but also depends mainly on the coupling between the set static bias magnetic field and AC （alterative current） magnetic field. The magnetostrictive sensor generation of longitudinal guided waves in circular pipes is designed in accordance to the developed model, and the longitudinal guided waves are acquired in the experiment. The experimental investigation, static bias magnetic field and AC magnetic field-dependence of generation of longitudinal guided waves by the magnetostrictive sensor applying different static bias magnetic field and AC magnetic field to the circular pipes, are carried out, respectively. The results show that there is a similar paracurve relation between static bias magnetic field applied to the circular pipes and the amplitude of longitudinal guided waves, which means the amplitude of longitudinal guided waves increases initially with increasing static bias magnetic field level, and reaches a maximum, and then decreases with further increase in the static bias magnetic field level. When guided waves propagating along the circular pipes, there is a non-linear relation between AC magnetic field applied to the circular pipes and the amplitude of longitudinal guided waves due to guided waves multi-modes and disperse characteristics.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2005年第10期174-179,共6页
Journal of Mechanical Engineering
基金
湖北省自然科学基金资助项目(2004ABA028)。
关键词
磁致伸缩效应
导波
无损检测
圆管
Magnetostrictive effect
Guided wave
Non-destructive testing
Circular pipes
