Viscoelastic vibration damping identification methods. Application to laminated glass

Vibration Analysis and Dynamic Characterization of Structural Glass Elements with Different Restraints Based on Operational Modal Analysis

“…A marked sensitivity of damping results was also noticed between accelerometers or laser estimations, for the same instrumented beams. The monolithic specimens were found to offer damping ratios of 0.81% and 0.53% respectively, from sensors or laser measurements [28]. Laser acquisitions for the still instrumented samples, but with cables removed, gave then evidence of a 0.35% damping capacity.…”

“…Later, Pelayo and Lopez-Aenlle [25] proposed a dynamic effective thickness formulation, for the reliable estimation of natural frequencies and damping ratios of multi-layered LG beams. To assess the viscous effect of PVB interlayers, OMA investigations were discussed for beam-like specimens with ideally rigid restraints, under different operational temperatures (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) • C the explored range). In [26], Zemanova et al carried out a wide set of parametric analytical calculations, aimed at assessing the frequency and loss factor estimations that can be derived from the modal analysis of beam-like LG elements with ideal supports, by considering several interlayer types (PVB, SentryGlas®(SG), or Ethyl Vinyl Acetate (EVA)).…”

“…In addition, the PIM approach resulted in typical advantages due to the use of non-contact instruments, but the study also emphasized the high sensitivity of experimental results to noise-induced errors. In this regard, Barredo et al [28] assessed different measurement techniques (i.e., laser measurements and accelerometers records) for the frequency and damping estimation of pinned-pinned, beam-like monolithic and LG samples (L = 1 m × B = 0.1 m their size, with 5.83 mm and 2 × 2.8 mm + 0.38 mm PVB the thicknesses of monolithic and LG specimens respectively). It was shown that stable estimations can be generally obtained in terms of frequencies, for both monolithic and LG specimens (less than 2-3% frequency variations, for the "instrumented" and "non-instrumented" samples), while the authors declared a marked sensitivity of the calculated damping ratios, to the presence of instruments (i.e., sensors of unknown size and weight, and related connection cables).…”

Parameter identification methods for visco- and hyperelastic material models

“…Further research on the time-and temperature dependent interlayer behaviour using the 'Dynamical-Mechanical-Thermal-Analysis' (DMTA) was done in Barredo et al (2011), Hooper (2011, Kothe (2013) and Kuntsche (2015). Viscoelastic material models for the interlayer material undergoing small deformations are given in Schuler (2003), Ensslen (2005), Sackmann (2008), Barredo et al (2011), Hooper (2011) and Kuntsche (2015). A commonly used model is the Generalized Maxwell Model, which is mathematically described by the 'Prony-series' and is implemented in many state-of-the-art FiniteElement-Analysis-Software to incorporate linear viscoelastic material behaviour.…”

Optimal cold bending of laminated glass

“…The shear coupling provided by the polymeric interlayer depends upon its viscoelastic response, which is highly time-and temperature-dependent (Louter et al, 2010;Bennison et al, 2005;Froli and Lani, 2011;Barredo et al, 2011;. In the design practice it is customary to rely upon approximate solutions, the most common of which considers the polymer as a linear elastic material, characterized by a proper secant shear modulus, calibrated according to temperature and characteristic duration of the design actions (Bennison and Stelzer, 2009).…”