压电单晶材料常数测量超声共振谱分析仪研究

Study on Resonant Ultrasound Spectroscopy for Measurement of Piezoelectric Single Crystals Material Constant

日益增长的新材料表征需求成为驱动超声共振谱分析仪发展的动力,而小尺寸、试样形状非规则等一系列个性化需求使得现有的超声共振谱分析仪已无法满足要求。该文借助实验室已有的通用超声测量仪器RAM-5000/SNAP,搭配相应的压电换能器,实现试样激发和共振谱数据采集,基于LabVIEW和MATLAB开发了界面友好的仪器操作界面、实现了Ritec仪器自动控制。此外,该文提出了一种将粒子群和模拟退火算法相结合的高性能优化算法,用于实现各向异性材料常数逆运算的求解。利用商用有限元软件COMSOL和Matlab接口程序,完成试样本征频率的正向计算和模态自动分析,可扩展到不规则、任意形状样本材料常数的测量。仪器的主要性能指标包括扫频范围为10kHz^33 MHz,扫频分辨率为50 Hz。另外,由于Ritec测量仪器兼具线性和非线性声学测量功能,故本仪器可以自然地扩展成为非线性超声共振谱分析仪。最后,测量了各向异性材料硅酸镓镧的弹性和压电材料常数,测量结果准确,验证了研制仪器的性能。

The growing demand for new material characterization has become the driving force behind the development of resonant ultrasound spectroscopy （RUS）, while a series of personalized requirements, such as small size and irregular shape, make the existing RUS unable to meet the requirements. This paper realizes the sample excitation and the data acquisition of resonance spectrum by using the conventional universal ultrasonic measuring instrument RAM 5000/SNAP equipped with the corresponding transducer, and a friendly interface instrument based on LabVIEW and MATLAB has been developed, which realizes the automatic control of the instruments. In addition, a high performance optimization algorithm combining particle swarm optimization with simulated annealing algorithm （PSO SA） is proposed to solve the inverse operation of anisotropic material constant. We have accomplished the positive calculation of the sample eigenfrequency and automatic mode analysis with the commercial finite element software COMSOL and Matlab interface program, which can be extended to the measurement of the sample material constants of irregular, arbitrary shape. The sweep range of the instrument is 10 kHz^33 MHz. The sweep resolution is 50 Hz. Since the Ritec measuring instrument has both linear and non linear acoustics measurements, it can naturally be expanded into a nonlinear RUS. The elastic constants and piezoelectric constants of anisotropic material of La3Ga5SiO14 （LGS） have been measured. The measurement results are accurate, which verifies the performance of the developed instrument.