大学物理 ›› 2017, Vol. 36 ›› Issue (10): 61-64.doi: 10. 16854 /j. cnki. 1000-0712. 2017. 10. 015

• 大学生园地 • 上一篇    下一篇

两种不同方法测量材料剪切模量

夏雨晴,叶晨钰,王彦昭,张雅男   

  1. 南京信息工程大学物理与光电工程学院,江苏南京210044
  • 出版日期:2017-10-20 发布日期:2017-10-20
  • 通讯作者: 张雅男,Email:phyzyn@ nuist. edu.cn
  • 作者简介:夏雨晴( 1996—) ,女,黑龙江哈尔滨人,南京信息工程大学物理与光电工程学院2014 级应用物理

Two different methods to measure the material shear modulus

XIA Yu-qing,YE Chen-yu,WANG Yan-zhao,ZHANG Ya-nan   

  1. School of Physics and Optoelectronics Engineering,Nanjing University of Information Science and Technology,Nanjing,Jiangsu 210044,China
  • Online:2017-10-20 Published:2017-10-20

摘要: 当一线圈悬挂于铜丝下,会因受到铜丝的扭转力矩而作简谐振动,测量简谐振动周期可以计算出铜丝的剪切模量. 线圈通电后,因处于地磁场中而受到地磁力矩,利用光杠杆放大原理,只要测量出线圈通电前后的微小偏转角度,也可计算出 铜丝的剪切模量. 为了减少测量时间,只要将捕捉到的线圈通电前后的简谐振动图像进行图像数值分析,便可在非常短的时 间内测量出线圈偏转角度,达到即时测量铜丝的剪切模量. 利用运动学、力学、光学、电磁学原理及图像分析技术综合方法测 量材料的剪切模量,既提高了测量精度,又降低了测量成本,易于操作,非常适合在大学物理教学中推广.

关键词: 扭转力矩, 简谐振动, 光杠杆, 地磁场, 图像分析技术

Abstract: When a coil hanging under the copper wire,due to the torque of the copper wire for harmonic vibration,simple harmonic vibration cycle can be calculated for the shear modulus of copper wire. After the coil is energized,it is affected by the geomagnetic moment in the earth s magnetic field. By using the optical lever amplification principle,the shear modulus of the copper wire can be calculated by measuring the small deflection angle before and after the coil is energized. In order to reduce the measurement time,the coil can be measured in a very short time by measuring the harmonic vibration image before and after the captured coil is energized,so as to measure the shear modulus of the copper wire. The method of kinematics,mechanics,optics,electromagnetism principle and image analysis technique is used to measure the shear modulus of the material,which improves the measurement accuracy,reduces the measurement cost and is easy to operate. It is very suitable for popularization in university physics teaching.

Key words: Torsional moment, simple harmonic vibration, optical lever, geomagnetic field, image analysis technique