金属纤维弹性模量的振动法测量

Measurement of Elastic Modulus for Metal Fiber by Vibration Method

摘要:

针对测量金属纤维弹性模量传统方法存在的局限，提出了一种用振动法测量金属纤维弹性模量的新方法。详细介绍了该方法的测量原理、测量装置、测量过程及误差分析。分别选择了钼丝和铂铱25合金纤维为测量对象，将被测材料制备成微悬臂梁试样，通过瞬态激励使悬臂梁产生短暂振荡，然后获得悬臂梁固有频率，再通过计算公式求出金属纤维材料的弹性模量。与静态拉伸法测量结果进行了比对，试验证明两者测试结果较为吻合。分析了悬臂梁长对测试结果的影响，结果表明：只有当梁长大于或等于8倍梁高 (直径) 时，这种影响才可忽略不计。

Abstract:

In order to overcome the limitations of traditional methods for measuring elastic modulus of the metal fiber, a novel method is proposed for measuring the elastic modulus of the metal fiber by vibration method．The measurement principle, apparatus, manipulation and error analysis were introduced. In this method, the measured metal fiber was generated in the form of a micro cantilever, and the cantilever can be vibrated for a short time when transient excitation is applied. The natural frequency of the cantilever can be used to calculate the elastic modulus of the material. Two kinds of materials, i.e. molybdenum wire and platinoiridium 25 fiber were tested in this work. The results prove that the measured values are consistent with that given in static tension method. The effect of beam length on determination of elastic modulus of materials was analyzed. The result shows that the influence of the ratio of L/d can be neglected only if the beam length is equal to or more than 8 times of the beam height (or diameter).