超声共振法测定圆柱体材料弹性常数的影响因素分析

为明确超声共振频谱分析法(RUS)测定圆柱体试样弹性常数的影响因素, 由此针对各向同性圆柱体开展实验, 观察圆柱体试样测量结果的分散性和稳定性, 且主要研究横纵比和有效模态数量对测量结果的影响, 并与拉伸试验的结果进行比较. 以测量结果标准差、变异系数和95%置信度下均值的区间估计3个指标来衡量结果的稳定性和分散性, 且从模态简并角度对实验结果进行分析. 最终结果表明, 当超声共振频谱分析法的有效模态数量在17左右、试样横纵比接近1时, 测量结果的稳定性和分散性较小.

The influence factors for measurements of elastic constants of isotropic steel cylinders by resonant ultrasound spectroscopy

Resonant ultrasound spectroscopy (RUS) is an efficient and accurate method to determine elastic constants of solids, but the results are affected by sample sizes and shapes. In order to study the distribution and stability of measurement data with cylindrical samples, experiments with isotropic cylinders of different aspect ratios and numbers of effective modes are conducted. The stability and distribution of measured results are examined with the standard deviation, the coefficient of variation and the boundaries of 95% confidence interval for the mean value. The results are further analyzed with the consideration of the degeneration of vibration modes and compared with those from tensile tests. The results show that the stability and distribution of measurements are small when the number of effective vibration modes is about 17 and the aspect ratio of samples is close to 1.