The propagation characteristics of viscoelastic waves have been investigated with a 6 mm diameter split Hopkinson pressure bar (SHPB) made of polymethyl methacrylate (PMMA). The strain signals in SHPB tests were improved by the pulse shaping technique. Based on the experimentally determined propagation coefficients, the amplitude attenuation and wave dispersion induced by viscoelastic effects at different impact velocities were quantitatively analyzed. The results indicate that the high-frequency harmonics attenuate faster in a higher phase velocity. With an increase in the impact velocity, the amplitude attenuation of the viscoelastic wave changes slightly during propagation, while the waveform dispersion gradually intensifies. A feasible method by waveform prediction was proposed to verify the validity and applicability of the propagation coefficient. The results indicate that the strain obtained from the small diameter viscoelastic SHPB can be effectively modified by utilizing the propagation coefficient. Furthermore, it is preferred to adopt the propagation coefficient obtained at low impact velocity for correction when the impact velocity varies. Moreover, the PMMA-steel bar impact test was performed to further illustrate the accuracy of the propagation coefficient and the effectiveness of the correction method.

中文翻译：

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直径为6 mm的粘弹性分裂霍普金森压力棒中的波衰减和色散及其校正方法

已经用直径为6 mm的由聚甲基丙烯酸甲酯（PMMA）制成的霍普金森压力棒（SHPB）研究了粘弹性波的传播特性。SHPB测试中的应变信号通过脉冲整形技术得到了改善。根据实验确定的传播系数，定量分析了在不同冲击速度下由粘弹性效应引起的振幅衰减和波频散。结果表明，高频谐波在较高的相速度下衰减更快。随着冲击速度的增加，粘弹性波的振幅衰减在传播过程中略有变化，而波形色散逐渐增强。提出了一种可行的波形预测方法，以验证传播系数的有效性和适用性。结果表明，利用传播系数可以有效地改变小直径粘弹性SHPB获得的应变。此外，优选的是，当冲击速度变化时，采用在低冲击速度下获得的传播系数进行校正。此外，进行了PMMA钢棒冲击试验，以进一步说明传播系数的准确性和校正方法的有效性。当冲击速度变化时，优选采用在低冲击速度下获得的传播系数进行校正。此外，进行了PMMA钢棒冲击试验，以进一步说明传播系数的准确性和校正方法的有效性。当冲击速度变化时，优选采用在低冲击速度下获得的传播系数进行校正。此外，进行了PMMA钢棒冲击试验，以进一步说明传播系数的准确性和校正方法的有效性。