Validation of an in-house developed acquisition system using a commercial acquisition system and the theoretical model of a clamped beam

Resumo

Vibration analysis is a technique that allows understanding through visualization of the frequency spectrum the propagation of vibrations in which a body is receiving from external forces. At a laboratory, the type of study allows the students to learn the concepts of this invisible force that is present in all the bodies and it also helps to understand how the material characteristics and the sample specimens geometry behave in these situations. Therefore, the objective of this project is the development of a didactic kit that allows the study of modal vibrations in test specimen such as beams, without the need of a vibration analysis equipment available in the market, that, in addition to the high cost, these equipments have reserved construction characteristics, that requires specialized training to understand how it works. For this acquisition system, it developed an accelerometer, analogical low-pass filters and an esp 32 microcontroller with A/D converter. The data processing was performed with a program developed in MatLab. A clamped beam was used to validade the project, in which a frequency analysis was performed. For this validation process, the kit results were compared against the mathematical model of the beam, whose first natural frequency is around 7Hz, and a commercial hardware available in the market. With these results, it was possible to evaluate the reliability and accuracy of the acquisition system in relation to computational models. Therefore, after extensive testing, this project can be manufactured by other institutions, bringing to the students in the educational environment the capacity to understand the structure and working of the equipment, besides learning how structures behave when submitted to many different vibration modes.