Introduction and Evaluation of a Damping Determination Method Based on the Short-Term Fourier Transform and Resampling (Stfr)

Abstract

In the present paper, a frequency domain method for damping determination is presented. The described method is especially developed for low damped systems with well separated eigenfrequencies. Using the Short-Term Fourier transform and Resampling (STFR) of the signal, decay curves of several mode shapes can be identified and amplitude-dependent damping values can be calculated. Additionally, two common methods for damping determination are explained briefly. Finally, the quality of the introduced method is evaluated comparing the variances of the identified damping values by means of different methods. In this context, the damping for beams clamped in a suspended way is analyzed. Stainless steel is used as the specimen material.

The investigation of viscous and structural damping for piezoelectric energy harvesters using only time-domain voltage measurements

“…A method known as Short-Term Fourier transform and Resampling (STFR) has recently been developed for natural frequency and damping extraction in free vibration tests using the time response [39]. A series of modifications are applied to the method in order to increase its accuracy for this study.…”

Analysis of an experimental setup for structural damping identification

“…The used methodology for damping identification was already presented by Hentschel et al (2015). In this paper, only a short overview of the used methodology will be given.…”

“…Furthermore, Bert (1973) offers an overview of methods for modeling, experimental determination and parameter identification of material damping. Within this work, the method presented by Hentschel et al (2015) is used for damping determination.…”

“…An automated impact excitation is used to enable the possibility of excitation in the vacuum chamber and to satisfy the criterion of reproducibility. A method for determining damping values including a short-term Fourier transform using resampling is briefly presented (see Hentschel et al, 2015). The used test rig, in combination with the analysis method, offers the possibility to identify the decay curve of one mode shape in order to calculate the damping values.…”

Design, modeling, and analysis of piezoelectric energy harvesters

“…The modified STFR (Short-Term Fourier transform and Resampling) is derived based on the STFR method in Ref. [182] that has been used for the modal analysis of nonpiezoelectric structures. Some modifications have been added to the primary STFR method so that the modified STFR has more capabilities to filter unwanted data and provide a more accurate curve fitting process.…”