Skip over navigation

 

Measuring Techniques in the Split Hopkinson Pressure-shear Bars

fangyun Lu (), Pengduo Zhao (), Chen R (NUDT China), banghai Jiang ()

Dynamic Behavior of Materials

Tue 10:45 - 12:15

Salomon 101

This paper presents measuring techniques in the split Hopkinson pressure-shear bars (SHPSB) we proposed in recently years. Because compression and bending elastic waves would propagate along the bars de-coupling, we designed measurements for the compression and shear loading independently. The compressive stress and compressive strain were measured based on the strain gauges on the bars with a half-bridge assembly, which eliminated influence of the bending waves. The techniques were validated by the numerical simulation and designed experiments. The shear stress was measured based on the piezoelectric effect by use of two quartz transducers (Y-cut quartz crystal with rotation angle 17.7°,or yzw/17.7°), which were embedded at the close-to-specimen end of the transmission bars. The technique was validated by numerical and experimental investigations on attenuation of the shear stress in the transmission bar. It is very difficult to establish a simple relationship between shear stress and shear strain as that in the Hopkinson torsion bars technique. Therefore, the shear strain was measured indirectly with a novel optical technique based on the luminous flux method. The technique was verified by the digital image processing at the same time.