The concentrically-layered photonic structure found in the tropical fruit Margaritaria nobilis serves as inspiration for photonic fibers with mechanically tunable band-gap. The fibers show the spectral filtering capabilities of a planar Bragg stack while the microscopic curvature decreases the strong directional chromaticity associated with flat multilayers. Elongation of the elastic fibers res...

We introduce a simplified model for a multi-material made up of two elastic bodies connected by a strong thin material layer whose stiffness grows as 1 . The model is obtained by identifying the Γ-limit of the stored strain energy functional of the physical problem when the thickness of the intermediate layer tends to zero. The intermediate layer behaves as a stiffening elastic membrane. Furthe...

In this paper, a new formulation based on Artificial Neural Networks (ANN) is presented for backcalculation of pavement layer moduli. In structural analysis of flexible pavements, the procedures as Layered Elastic Theory, Equivalent Layer Thickness (ELT), and Finite Elements Method (FEM) generally have complex formulations and give approximate results. Therefore, it is extremely difficult to pe...

Surface-modification of the elastomer poly(dimethylsiloxane) by exposure to oxygen plasma for four minutes creates a thin, stiff film. In this study, the thickness and mechanical properties of this surface-modified layer were determined. Using the phase image capabilities of a tapping-mode atomic-force microscope, the surface-modified region was distinguished from the bulk PDMS; specifically, i...

We develop a loosely coupled fluid-structure interaction finite element solver based on the Lie operator splitting scheme. The scheme is applied to the interaction between an incompressible, viscous, Newtonian fluid, and a multilayered structure, which consists of a thin elastic layer and a thick poroelastic material. The thin layer is modeled using the linearly elastic Koiter membrane model, w...

The microstructures of chemical vapor deposited coatings on four tool inserts have been comprehensively characterized using electron backscatter diffraction mapping and these data have been used as input for finite element models used to calculate the residual thermal strains in the coatings. The results indicate that the thermal strains and stored elastic energy in the α-Al2O3 layer are larger...

Electric-field-induced instabilities in thin bilayers composed of either purely viscous or purely elastic films resting on a solid substrate are studied. In contrast to the electric-field-induced instability in a single elastic film, the length scale of the instability for elastic bilayers can be tuned by changing the ratios of the shear moduli, thicknesses, and dielectric permittivities of the...

The interlaminar-toughened CFRP composite, T800H/3900-2, has interlaminar resin layers, whose thickness is about 20 mm. The interlaminar layer was evaluated quantitatively using an ultrasonic micro-spectrometer (UMSM) for the determination of the elastic constants, which is quite difficult by other techniques. At first, the composite was ground to remove the outermost CFRP layer, and the interl...

Purely elastic, partially and fully plastic stress states in a thick-walled spherical pressure vessel with an inner functionally graded material (FG) coating subjected to internal and external pressures are developed analytically in this paper. The modulus of elasticity and the uniaxial yield limit of the FG coating layer are considered to vary nonlinearly through the thickness. Using Tresca’s ...