Experimental device and method for measuring Young modulus of metal wire according to simple harmonic vibration

Abstract

An experimental device and method for measuring Young's modulus of metal wire based on simple harmonic vibration, relating to a measuring device and method for Young's modulus, the present invention solves the experimental principle of measuring Young's modulus of metal wire in current university physics experiments Relatively simple and abstract problems. The device of the present invention includes setting a crossbeam on the upper end of the bracket, setting an upper chuck and a force-sensitive sensor in the middle of the crossbeam, connecting the two ends of the metal wire to the force-sensitive sensor and the lower chuck respectively, and fixing the lower chuck to a metal frame with an internal fixed iron block. Together, the measuring device is composed of a differential bridge composed of four capacitors consisting of a fixed plate and a movable plate, an adjustable AC voltage source, a voltage amplifying device, and a digital oscilloscope; The period of the bridge output voltage waveform is obtained from the period of the simple harmonic vibration of the wire spring vibrator, which is substituted into the formula to calculate the Young's modulus of the wire. The invention is applicable to the measurement of the Young's modulus of the 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 according to simple harmonic vibration. 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 ...

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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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