和田玉超声波数值模拟分析及回波信号特征分析

Numerical Simulation Analysis and Echo Signal Characterisation of Hetian Jade Ultrasonic Waves

和田玉的无损检测对其价值有着重大的意义,可为后续的加工、雕刻和收藏提供有力的依据.针对目前和田玉的力学性能以及声学特性,根据各向同性介质的线弹性本构方程,建立了压电超声无损检测和田玉的有限元仿真模型,对回波信号特征进行了时域分析、频域分析和EMD分解,并计算出EMD分解后各IMF分量的能量熵.通过对仿真模型的波场快照和时域分析,验证了仿真模型的正确性;通过对仿真信号以及试验信号的时域分析以及EMD分解,结果显示仿真信号的特征变化规律与试验信号的变化规律保持一致.

The nondestructive testing of Hetian jade is of great significance to its value and can provide a strong basis for subsequent processing,carving and collecting.The finite element simulation model of piezoelectric ultrasonic nondestructive detection of Hetian jade was established based on the linear elastic principal equation of isotropic medium for the mechanical and acoustic properties of Hetian jade,and the time domain analysis,frequency domain analysis and EMD decomposition of the echo signal characteristics were carried out,and the energy entropy of each IMF component after the EMD decomposition was calculated.The time domain analysis and EMD decomposition of the simulated signal and the experimental signal show that the change law of the simulated signal is consistent with the change law of the experimental signal,which lays the foundation for the ultrasonic NDT of Hetian jade.