Estimation of material functions using system identification techniques

Effect of magnetic field on viscoelastic wave characteristics

“…In general, literature [31][32][33] shows that to use rod theory as sufficient reliable, the wavelength should be greater than approximately 5-10 times the rod diameter. From Figure 6 As it is known, the Love rod theory does not give accurate estimation in the range of relatively high frequencies since it does not take cross-section warping into account, so are no longer safe enough the results of the analysis presented here in the point of view the geometrical effects, in high-frequency regime.…”

“…In general, literature 31–33 shows that to use rod theory as sufficient reliable, the wavelength should be greater than approximately 5–10 times the rod diameter. From Figure 6(a), the wavelength of longitudinal waves in the 20-mm viscoelastic rod are 0.141 m (i.e., 7d) at 26.5 kHz, approximately 0.14 m (7d) at 18.5 kHz, and 0.143 m (7d) at 14.5 kHz, for Hy = 10 8 A/m, 0.5 × 10 8 A/m and 0, respectively.…”

Experimental evaluation of different natural cold sinks integrated into a concrete façade

“…Especially, when it is working with real measurements in real buildings. This time base has been chosen because being an experiment in free evolution for a day is a sufficiently homogeneous time base and, in addition, it is a time base of enormous applicability for real buildings because it reduces monitoring requirements [87,88].…”

Subspace model identification of guided wave propagation in metallic plates

“…Lessening the dependence on the orthodox physical principles and adopting numerically friendly assumptions, semiphysical or parametric models have been strategically considered. For example, a parametric model with complex modulus is identified by a least squares solution [8]; a heuristic transmission line model is proposed for modeling wave propagation along lap joints [9]. There is an interesting task of estimation of a transfer function, between white-noise excitation and propagating waves in a thin aluminum strip [10]; the estimated transfer function is a data-fitted auto-regressive with exogenous input (ARX) model and thus considered a data-driven black-box model not directly related to the underlying physical principles of wave propagation.…”