Experiment device and method adopting resonance principle to measure Young modulus of metal wire

Abstract

The invention relates to an experiment device and method adopting a resonance principle to measure the Young modulus of a metal wire, relates to a Young modulus measuring device and method, and aims to solve the problems that in the conventional university physical experiments, the experiment principle for measuring metal wire Young modulus is single and abstract, and the telescope is hard to adjust. The device comprises a crossbeam, which is arranged on the upper end of a support. An upper clamping head and a vibration generator are arranged on the middle of the crossbeam. Two ends of a metal wire are respectively connected to the vibration generator and a metal frame. The vibration generator is connected to a signal source. A measuring device is composed of a differential bridge composed of four magnetic sensitive resistors, an alternating voltage source, an amplification device, and an oscilloscope. According to the method, the sinusoidal signals are converted into mechanical vibration by the vibration generator so as to force a metal wire spring oscillator to vibrate. The differential bridge composed of magnetic sensitive resistors is converted into electric signals. The signal frequency is adjusted. When the waveform amplitude is the largest, the inherent frequency of the metal wire spring oscillator is obtained. Then the inherent frequency is substituted into a formula to calculate the Young modulus of the metal wire. The provided method is suitable for measuring the Young modulus of a metal wire.

Description

technical field [0001] The invention relates to a university physics experiment device, in particular to an experiment device and method for measuring the Young's modulus of a metal wire by using the resonance principle. Background technique [0002] The change in shape of a solid under the action of an external force is called deformation. It can be divided into elastic deformation and normative deformation. The deformation that an object can completely return to its original shape after the external force is removed is called elastic deformation. If the external force applied to the object is too large, so that after the external force is removed, the object cannot completely return to its original shape, leaving residual deformation, which is called normative deformation. In this experiment, only elastic deformation is studied. Therefore, the magnitude of the external force should be controlled to ensure that the object can return to its original shape after the extern...

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Problems solved by technology

[0005] First, the Young's modulus of metal wire is usually measured by static stretching method, and the principle is relatively simple

[0006] Second, according to the optical lever amplification principle, the tiny elongation of the metal wire is measured through the amplification system composed of optical levers, telescopes and rulers. Although the method is ingenious, the principle is abstract and difficult to understand. The adjustment of the telescope is relatively difficult. Notes There are many, and it is very easy to get tired and make mistakes in the data, which will affect the accuracy of the measurement results.

[0007] Third, weights are generally used to apply tension to the wire, and the nominal mass of the weights is used to calculate the tension inaccurately, thus affecting the accuracy of the experimental results

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