Experiment device and method for measuring Young modulus of metal wire based on resonance principle

Abstract

The invention discloses an experiment device and method for measuring the Young modulus of a metal wire based on a resonance principle, 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 provided device comprises a crossbeam, which is arranged on the upper end of a support. A platform is arranged on the middle of the crossbeam. Two ends of a metal wire are respectively connected to a vibration generator and an iron block. The vibration generator is connected to a signal source. A laser device is arranged on a scale. The sinusoidal signals are converted into mechanical vibration by the vibration generator so as to force a metal wire spring oscillator to vibrate, the vibration is amplified by an amplification system, which is composed of a laser device and an optical lever, through the vibration, the laser beams are reflected by the flat mirror of the optical lever to form light spot vibration on the scale, the signal frequency is adjusted, when the vibration amplitude is the largest, the inherent frequency of the metal wire spring oscillator can be obtained, and the inherent frequency is substituted into a formula to calculate the Young modulus. 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, in particular to an experimental device and method for measuring the Young's modulus of a metal wire based on 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 external fo...

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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

[0008] Fourth, the plane mirror of the optical lever is generally made of glass, which is easily damaged during the experiment

[0009] Fifth, the scale illuminator generally adopts a small straight tube fluorescent lamp, the brightness is not easy to adjust, and it is easy to be damaged, and because there is a capacitor in the power supply device, if it is not discharged in time after use, the experimenter will be easily shocked by electric shock

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