超声脉冲法测量固体材料声速实验的扩展与升级

Measuring sound velocity in solid medium by ultrasonic pulse method

根据声速与材料弹性常量之间满足的克里斯托菲尔方程,利用超声脉冲法测量了超磁致伸缩材料中超声波沿不同方向传播的声速,计算出超磁致伸缩材料的弹性常量.利用电磁铁激发均匀的外磁场,测量了超磁致伸缩材料中超声波沿不同方向传播的声速与外磁场的关系,研究了超磁致伸缩材料的弹性常量随外磁场的变化规律.通过对传统固体介质声速测量实验内容的扩展与升级,不仅加深了学生对超声脉冲法测量声速原理的理解,还使传统的实验项目焕发了新的生命力.

According to the Christofel equation which satisfies the relationship between acoustic velocity and elastic constant,the ultrasonic pulse method was used to measure the acoustic velocity of ultrasonic wave in giant magnetostrictive material.Using electromagnets to stimulate uniform external magnetic field(0〜106 kA/m),the dependences of the ultrasonic velocity in three different directions on the external magnetic field were measured,and the elastic constants of the giant magnetostrictive material were calculated for varied external magnetic field.By this extension and upgrade of the traditional solid medium velocity measurement experiment,students'understanding on the principle of ultrasonic velocity measurement were deepen,and the traditional experimental project was given newvitality.