Static and dynamic effective thickness in five-layered glass plates

Abstract

In the last years, the effective thickness concept has been used to calculate deflections, stresses and modal parameters in laminated glass beams and plates, which consists of using a monolithic model with equivalent bending properties to a laminated element, i.e. the thickness of the equivalent monolithic model is time and temperature dependent. Multi-layered laminated glass panels are those with at least three monolithic glass layers and two viscoelastic interlayers which are commonly used in floors, roofs and other applications where a high level of security is required. In this paper, a static deflection effective stiffness for a laminated glass plate consisting of three glass layers and two polymeric interlayers is derived. This static effective thickness is then extended to the frequency domain using the correspondence principle. The models are validated by static experimental tests and operational modal tests carried out on a rectangular multi-layered laminated glass plate pinned supported at the four corners.

Investigating the viscous damping effects on the propagation of Rayleigh waves in a three-layered inhomogeneous plate

“…Also for the eigenfunctions, the solutions given in equation (15) via the conditions in equations ( 9)-( 10)for y0 are revealed to be as follows:…”

“…For, instance, laminated glasses consists of thin soft core layer and stiff facings are used in glazing applications; photovoltaic panels are made of light core layer with stiff facings and used in solar energy; while the classical sandwich plates normally emerged with light core layer and stiff facings, with a variety of applications including in elastic beams [11,12]. Mathematically, a quite number of studies have been reported in the literature in regard to layered plates comprising of the harmonic wave propagation in layered elastic sandwiches [11], elastic waves dispersion in threelayered plates [12], low-frequency motions of elastic multicomponent structures [13], analysis of composite sandwich plates of a five-layered nature with viscoelastic cores [14] and the dynamicity of five-layered plates for various thicknesses made of glass material [15], see also [16][17][18][19][20][21][22][23] among others and the references therein. Besides, viscous damping effects in regards to propagation of elastic waves in layered media has not been found in the literature, of which is it believed to affect such propagation considerably.…”

Viscoelastic characterization of seven laminated glass interlayer materials from static tests

“…The shear behaviour of the interlayer material affects the deformability and the load-bearing capacity of laminated glass plates [1], as well as its post-breakage behaviour [2][3][4]. In other words, the polymeric interlayer governs the general behaviour of laminated glass; hence, its importance for an adequate design and calculation of laminated glass structural elements.…”

“…Interlayer materials are viscoelastic, which means that their stiffness and mechanical response depends on the load duration and working temperature [5][6][7]. Therefore, the mechanical properties of laminated glass also depend, at least, on these two factors [1,8,9].…”

Asymptotic approach to anti‐plane dynamic problem of asymmetric three‐layered composite plate

“…1 Many researchers have published quite a number of articles with regards to multilayered media including the thin-walled elastics structures, 2 the analysis of a three-layered plate with a thin soft core, 3 the parametric analysis of the inhomogeneous periodic waveguides, 4 the long-wave asymptotic approximations in waveguides and periodic media, 5 the wave propagation in laminated composites and sandwiches [6][7][8] and the low-frequency approximations associated with both the plane and anti-plane shear motions in a symmetric three-layered plate. [9][10][11] Other related studies include the low-frequency determination in multi-component elastic structures, 12 the asymptotic approach to plates with mixed boundary conditions, 13 the successful introduction and examination of a unification of parameters procedure with regards to five-layered plates with alternating layers, 14 and other different considerations on the five-layered structures with regards to various phenomena including their dynamic and static effective lengths and the stress distribution based on certain classical deformation theories 15,16 among others.…”