微型加速度传感器用于金属棒弹性模量测量

Measurement of a metallic rod's elastic modulus with the cantilever vibration monitored by a mini-accelerometer

基于振动理论给出的悬臂梁弯曲自由振动的一阶固有频率与材料弹性模量的关系,提出用微型加速度传感器测量悬臂梁单端自由振动的频率,并在自行搭建的实验装置上对钢棒的弹性模量进行了测量,分析了影响测量结果准确性的因素.最终实验结果与手册查询到的对照值十分吻合,测量的相对不确定度为0.66%.本实验原理清晰、装置构成简单、操作简便、结果较精确,适于教学使用或工业现场检测之用.

Natural frequency of a cantilever beam can be linked to the elastic modulus of the beam material. With a mini-accelerometer mounted on the free end, the bending vibration frequency of a steel rod is obtained, and then the elastic modulus of the rod steel is derived. The added mass of accelerometer to the beam has been taken into account to modify the frequency modulus relationship. Final measurement result of the elastic modulus is quite consistent with the given value, accompanying a relative uncertainty of 0.66%. The principle of the experiment is clear and the construction of used setup is simple. More convenience of minimum operation comes with the mentioned advantages.