Search results for "laminate"

Enhancement of Electronic and Optical Properties of ZnO/Al2O3 Nanolaminate Coated Electrospun Nanofibers

2016

International audience; Nanolaminates are new class of promising nanomaterials with outstanding properties. Here we explored on the tuning of structural properties and the enhancement of electronic and optical properties of 1D PAN ZnO/Al2O3 nanolaminates designed by atomic layer deposition (ALD) and electrospinning. The influence of ZnO/Al2O3 bilayer thicknesses on the fundamental properties of 1D PAN ZnO/Al2O3 nanolaminates has been investigated. Due to the quantum confinement effect, the shift of XPS peaks to higher energies has been observed. Work function of Al2O3 was mostly independent of the bilayers number, whereas the ZnO work function decreased with an increase of the bilayer numbe…

Abrupt Alnus population decline at the end of the first millennium CE in Europe - The event ecology, possible causes and implications

2019

The study, based on the examination of 70 published and unpublished pollen profiles from Poland and supplementary data from the surrounding regions, shows that an abrupt, episodic Alnus population decline at the end of the first millennium CE was a much more widespread event than has been previously reported, spanning large areas of the temperate and boreal zones in Europe. The data from Poland suggest that the decline was roughly synchronous and most likely occurred between the 9th and 10th centuries, with strong indications for the 10th century. The pollen data indicate that human impacts were not a major factor in the event. Instead, we hypothesize that one or a series of abrupt climatic…

Mixed finite elements for nonlocal elastic multilayered composite plate refined theories

2020

Abstract A novel mixed finite element formulation for the layerwise analysis of nonlocal multilayered composite plates is presented. The finite elements are formulated starting from the weak form of a set of governing equations for the laminate layers that were deduced via the Reissner Mixed Variational Theorem. The primary variables, namely displacements and out-of-plane stresses, are expressed at layer level as through-the-thickness expansions of suitable selected functions with coefficients approximated by the finite element scheme. The through-the-thickness expansion order is considered as a free parameter. This way, finite elements for different refined higher order plate theories can …

Sensitivity analysis of a piezoelectric SHM system for delaminated composite flange-skin structure

2013

Influence of Nylon 6,6 nanofiber mats on cure behavior and properties of CFR epoxy resin

2014

In this work Nylon 6,6 nanofibrous mats produced by electrospinning were used as interlayers in carbon fiber reinforced laminates. A high crossilinked epoxy resin was chosen as matrix. The effects of polymeric mats on cure behavior, thermal and delamination properties of the composite laminates were investigated.

COMPRESSIVE BEHAVIOR OF LAMINATED GLASS COLUMNS

2014

This paper examines the behavior in compression of glass columns having tee (T) transverse cross-sections. The work highlights the issues recurring in the design of glass columns in rapid diffusion in the transparent architecture such as: - flexural and torsional buckling; - long-term effects and effects related to the temperature; - glued connections between single panels. In the work expressions are given for the calculation of the loadcarrying capacity of columns. The cases of full connection and absence of connection between the panels are analyzed and discussed. The comparison between the analytical and the experimental results highlights that in the case of glass columns with T cross-…

Compressive behaviour of laminated glass columns with T cross-sections

2014

Load Carrying Capacity of Glass Columns with Rectangular, T and X Transverse Cross-sections

2014

In this study, the load carrying capacities of glass columns with rectangular, T and X cross-sections having different lengths were calculated. The proposed analytical procedure allows to calculate the load carrying capacity associated with strength of transverse cross-section including local and global flexural and/or torsional buckling phenomenon. Moreover, initial imperfections and time dependant effects, the latter associated with the viscoelastic behaviour of interlayer (PVB), were included in the model as suggested in the literature. Those effects were calculated by introducing the equivalent thickness of glass panels, which takes into account the shear modulus of PVB and the viscolea…

Analytical solution for the transient response of symmetric magnetoelectric laminated beams

2010

In this paper an analytical solution is presented for the forced vibration problem of magnetoelectric symmetric laminated beams. In deriving the mathematical model the Timoshenko’s beam theory is used and the electric and magnetic fields are assumed to be quasi-static. The model is written for a magnetoelectric sensing device by applying proper magnetoelectric boundary conditions on the beam top and bottom surfaces. The model highlights that the magneto-electro-mechanical couplings affect the bending stiffness and that the magnetoelectric inputs can be treated as equivalent bending moments. Forced vibration analyses are presented to assess the reliability of the solution.

A two-node finite element for linear magneto-electric laminated timoshenko beams

2012

A new finite element is presented for linear magnetoelectric straight laminated beam subject to the assumptions of quasi-steady electromagnetic state. The mechanical model is based upon Timoshenko beam theory to account for shear deformation influences. The electromagnetic stacking sequence is proved to enter the equivalent elastic problem by affecting both the stiffness properties of the beam, in terms of axial and flexural coupling, and by modifying the mechanical boundary conditions as distributed loads. Shape functions are first written for the generalized beam mean-line kinematical quantities in such a way the obtained strain field fulfills the homogeneous governing equations of the eq…