摘要
声发射传感器的校准是声发射定量检测技术的前提,互易法和表面脉冲法是目前通常采用的两种校准方法,为探讨其一致性,从互易常数入手,比较表面波互易常数和表面脉冲法中的等效互易常数。通过加载力的等效处理、利用激光测振仪测量质点振速,获得法向速度和所加力脉冲的时域和频域分量,计算得到等效互易常数。同时,建立互易法和表面脉冲法校准系统,对实验结果进行对比分析。互易常数与等效互易常数的计算结果和基于校准系统的实验结果表明,互易法和表面脉冲法之间具有较好的一致性,电信号激励声发射换能器所引起的径向谐振产生的影响,对于互易校准而言可以忽略。
Acoustic emission sensor calibration is the precondition for the quantitative detection of acoustic emission technique, reciprocity and surface pulse methods are main calibration methods. In order to investigate and verify the consistency of the two methods, reciprocity coefficient and equivalent reciprocity coefficient in surface pulse method of Rayleigh wave werecalculated and compared. Time domain and frequency domain components of the force pulse and the corresponding velocity were obtained respectively by equivalent treatment of loading force and laser vibrometer. Based on the physical meaning of reciprocity coefficient, equivalent reciprocity coefficient is calculated by the ratio of the normal velocity to the exciting force per unit. Meanwhile the calibration systems of reciprocity and surface pulse method were established, the calibration results were compared and analyzed. Real and equivalent reciprocity coefficient calculations, as well as the experimental results based on the calibration system, showed good agreements between reciprocity and surface pulse method. The results also showed that effect of radial resonance of acoustic emission transducers caused by electrical excitation can be ignored in reciprocity calibration.
出处
《计量学报》
CSCD
北大核心
2017年第5期621-625,共5页
Acta Metrologica Sinica
基金
国家自然科学基金(51205378
51575502)
公益性行业科研项目(201301010)
关键词
计量学
声发射
等效互易常数
校准
metrology
acoustic emission
equivalent reciprocity coefficient
calibration
