Experimental device and experimental method for measuring Young modulus with simple harmonic vibration beam bending method

Abstract

An experimental device and method for measuring Young's modulus by the beam bending method of simple harmonic vibration relates to a Young's modulus measuring device and method. The principle is single and abstract, and the adjustment of the telescope is difficult. The device of the present invention includes setting two uprights on the base, and the two ends of a metal beam with a rectangular cross-section are freely straddled on the knife edge at the upper end of the uprights, a copper frame is placed on the metal beam, and a force-sensitive sensor, a movable armature and an iron block are set at the lower end , the electromagnet device is arranged below, and the measuring device is composed of a differential bridge formed by two inductance coils and two adjustable resistors, an adjustable AC voltage source, a voltage amplification device, and a digital oscilloscope; the method of the present invention measures the period by a digital oscilloscope The cycle of the output voltage waveform of the bridge that changes permanently is obtained to obtain the cycle of the simple harmonic vibration of the metal beam spring vibrator, which is substituted into the formula to calculate the Young's modulus of the metal material. The invention is applicable to the measurement of Young's modulus.

Description

technical field [0001] The invention relates to a university physics experiment device, in particular to an experiment device and method for measuring Young's modulus by a simple harmonic vibration beam bending method. 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...

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Problems solved by technology

[0005] First, the static tensile method is usually used to measure the Young's modulus of metal materials, and the principle is relatively simple

[0006] Second, according to the optical lever amplification principle, the sag of the midpoint of the rectangular cross-section metal beam is measured through the amplification system composed of the optical lever, the telescope and the ruler. Although the method is ingenious, the principle is abstract and difficult to understand, and the adjustment of the telescope is relatively difficult. It is large, and there are many precautions, 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 metal beams, and the calculation of tension with the nominal mass of weights is inaccurate, thus affecting the accuracy of experimental results

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