Experimental device and method for measuring Young modulus according to simple harmonic vibration beam bending method

Abstract

The invention discloses an experimental device and method for measuring the Young modulus according to a simple harmonic vibration beam bending method, and relates to a Young modulus measuring device and method. The device and method are aimed at solving the problems that in current college physics experiments, the experiment for measuring the Young modulus through the beam bending method is simple and abstract in theory and the adjustment difficulty of a telescope is large. According to the device, two stand columns are arranged on a base, the two ends of a rectangular-section metal beam are freely arranged on tool edges of the upper ends of the stand columns in a striding mode, the metal beam is sleeved with a copper frame, the lower end of the metal beam is provided with a force sensor and a metal frame, an iron block is fixed into the metal frame, an electromagnet device is arranged below the metal beam, the measuring device is composed of a differential bridge, an adjustable AC voltage source, a voltage amplifying device, a digital oscilloscope and the like, the differential bridge is composed of four capacitors, and each capacitor is composed of a fixed electrode plate and a movable electrode plate. By means of the method, the voltage waveform output cycle of the periodically-changing bridge is measured through the digital oscilloscope, and the simple harmonic vibration cycle of a spring oscillator of the metal beam is obtained and substituted into a formula so that the Young modulus can be calculated. The device and method are suitable for measuring the Young 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 according to the 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 ...

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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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