DESIGN AND IMPLEMENTATION OF A SPRING-MASS RESONATOR FOR TEACHING ASSISTANCE

Abstract

Over time, the issue of maintaining, restoring, and consolidating structural elements has become increasingly important for engineers and designers in the mechanical engineering sector. Many structures built in the past using outdated methods are now considered structurally unsafe according to modern standards. Replacing these structural elements is often costly and time-consuming, so strengthening has become the preferred method to enhance load capacity and extend the lifespan of these structures.

The purpose of this work is to introduce the concept of vibration to young people and explain how exciting it is to study this field. The goal is to calculate the vibration behavior of different materials when subjected to external excitation. The method involves characterizing the resonant response of a spring-mass system that is excited by a sine-wave forcing term applied as a vertical force to the suspended mass. The prototype of the testing machine is made from second-hand materials that are readily available. The young modulus is obtained from the resonance frequency, and the non-linear coefficient is calculated using the backbone approach from resonance profile variations as a function of the forcing term amplitude. The method is highly sensitive, to the point that a maximum excitation amplitude of the order of the non-linear coefficient is required. The testing machine provides the necessary sensitivity at such small excitation amplitudes and the capability of evaluating very small damping values, as expected in high strength low damping materials. The sensitivity is ensured by an optical position sensor.