A simply supported beam vibration experiment demonstration instrument

Abstract

The invention aims to provide a demonstrating instrument for a simply supported beam vibration experiment. In a physics teaching process, vibration of an infinite-degree-of-freedom object is usually demonstrated through vibrations of simply supported beams or cantilever beams. The simply supported beams in the demonstrating instrument vibrate under vibration excitations of vibration exciters, when the vibration excitation frequency equals to an inherent frequency of a specific phase, the beams resonate, and the vibrating form is approximate to a corresponding principal vibration mode. When the vibration excitation frequency of the vibration exciters is increased slowly, variation of the beams from a first-phase principal vibration mode to a second-phase and a third-phase principal vibration mode can be shown. The demonstrating instrument for the simply supported beam vibration experiment has the advantages that by amplifying displacement and vibration of the simply supported beams by directly demonstrating the principal vibration modes in various phases of the simply supported beams, experimental explanation in modeled teaching for the infinite-degree-of-freedom object vibration is facilitated, and by comparing and observing the multi-phase vibration modes, understanding to modal superposition on vibration is enhanced.

Description

technical field [0001] The invention belongs to the field of physics teaching appliances, in particular to a simply supported beam vibration experiment demonstration, belonging to teaching experiment appliances. Background technique [0002] In the process of physics teaching, the model of a spring oscillator is generally used to demonstrate the vibration of a single-degree-of-freedom object. For the vibration of an object with infinite degrees of freedom, it is generally demonstrated by a simply supported beam or a cantilever beam. [0003] During the vibration process of an object with infinite degrees of freedom, its natural frequency and main vibration mode are two important parameters to describe the vibration, which are only related to the nature of the structure itself and reflect the inherent properties of the structure. The so-called main vibration shape is the vibration displacement ratio of each point on the vibrating body at the same time, and its main vibration...

AI Technical Summary

Problems solved by technology

[0005] Since the amplitude of each point is small and the speed is fast during the vibration process of the simply supported beam, it is difficult to observe the mode shapes of each order intuitively.

In the existing experiments, the displacement of each point is often recorded by the strain sensor, and the recorded data is drawn on the coordinates as a graph corresponding to the main vibration mode, so as to facilitate observation. However, this observation method lacks intuition due to the intermediate processing of the data.

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