DESIGN AND APPLICATIONS OF PIEZOELECTRIC CRYSTALS TRANSDUCER IN DYNAMIC EXPERIMENTS

Various piezoelectric crystals are widely used in many fields such as electronics industry, information transmission to achieve energy conversion, frequency control or as sensors and so on. With the unique piezoelectric properties and high frequency response, piezoelectric crystals have been used as force transducer in high strain-rate experiments to test dynamic stresses. Among them, quartz crystal has been used in split Hopkinson pressure bars (SHPB) for axial stress measurement, and in gas gun experiments as the shock wave pressure transducer. Meanwhile, with the anisotropic properties, it is possible to design a special rotated cut direction for the crystals to get a required piezoelectric response to selected stress. In this paper, we propose a design of shear transducer in split pressure-shear Hopkinson bars (SHPSB), by analyzing the wave propagation characteristics with a desired pure vibration mode in anisotropic crystals, and the basic principles of piezoelectric effect with independent response to the shear stress. Two typical shear transducers, which are made of 17.705° rotated Y-cut quartz and 165.44° rotated Y-cut lithium niobate respectively, are achieved finally.