The application of the log decrement and the log increment to identify parameters of an oscillation

Joo J.M. · Complexity and Fractality in Human Change and Beyond (2025)

Resumen

Based on the technique of logarithmic decrement to identify the parameters of a damped oscillation, an educational virtual lab to determine the parameters of a stimulated oscillation has also been developed. At the experiment's opening, the virtual lab's operator enters the input data of the oscillation to be simulated, or these data may be set at random by the virtual lab. Then, the x(t) curve - displacement versus time- is displayed on a computer screen. Since identifying the parameters of the oscillation is based on its maximum amplitudes, to obtain theoretical parameters, the virtual lab identifies the maximums of x(t) and, from these, it computes the logarithmic decrement (increment) to get the damping -whether positive or negative- the system is undergoing, next from this damping the theoretical parameters of the oscillation are automatically deduced. When the operator of the virtual lab activates the "manual mode," he mouse-clicksthe extremes of the x(t) curve appearing on the screen. Once 10 successive extremes have been clicked, the module computes the experimental (manual) oscillation parameters. At the end of the experiment, the virtual lab shows the theoretical and experimental results. Suppose the operator has carefully mouse-clicked the extremes of x(t). In that case, his experimental results will be verified as close or equal to the input data and those calculated by the simulator.

Instituciones: Universidad Nacional Mayor de San Marcos