We investigate the spectrum and the dispersion relation of the Schrdinger operator with point scatterers on a triangular lattice and a honeycomb lattice. We prove that the low-level dispersion bands have conic singularities near Dirac points, which are the vertices of the first Brillouin Zone. The existence of such conic dispersion bands plays an important role in various electronic properties ...

The external quantum efficiency of solar cells can be improved by using texturing pyramid- and honeycomb-like structures with minimum reflection. In this study, we investigated the reflection properties of texturing structures through rigorous coupled-wave analysis and the three-dimensional finite-difference time domains (FDTD) method to analyze close-packed texturing structures. We also demons...

This paper presents a finite-element analysis of honeycomb and re-entrant honeycomb structures made of a two-phase composite material which is optimized with respect to selected parameters. It is shown that some distributions of each phase in the composite material result in the counter-intuitive mechanical behaviour of the structures. In particular, negative values of effective Poisson's ratio...

This paper describes a new concept of an active honeycomb structure for morphing wingtip applications based on tubular inflatable systems and an auxetic cellular structure. A work-energy model to predict the output honeycomb displacement versus input pressure is developed together with a finite element formulation, and the results are compared with the data obtained from a small-scale example o...

In this paper, we introduce a new subdivision scheme which we call honeycomb subdivision. After one iteration of the scheme each vertex becomes exactly 3-valent and with consecutive applications regular regions strongly resembles a honeycomb. This scheme can be considered as a dual for triangle schemes. The major advantage of the new scheme is that it creates a natural looking mesh structure.

To solve the problem of critical buckling in the structural analysis and design of the new long-span hollow core roof architecture proposed in this paper (referred to as a "honeycomb panel structural system" (HSSS)), lateral compression tests and finite element analyses were employed in this study to examine the lateral compressive buckling performance of this new type of honeycomb panel with d...

In the study of honeycomb crushing under quasistatic loading, two parameters are important, the mean crushing stress and the wavelength of the folding mode. The previous theoretical models did not consider the true cylindrical curvature effects and the flow stress in the folding mode of honeycomb material. The present paper introduces a modification on Wierzbicki’s model based on considering tw...

An increased use of free form surfaces in design often results to mass customised components and structural systems which are complex to assemble and expensive to produce. Often to resolve these forms, a tessellation algorithm is used to break the geometry down to manageable components which can be fabricated individually. The issue that can arise is the production of ...

This paper explores the effect of inlet flow modifcation on the cavitating and noncavitating performance of two cavitating inducers, one of simple helical design and the other a model of the low-pressure LOX pump in the Space Shuttle Main Engine. The modifications were generated by sections of honeycomb, both uniform and nonuniform. Signifcant improvement in the performance over a wide range of...

The effect of the core cell shape on shock absorption characteristics of biomimetically inspired honeycomb structures has been numerically investigated. The finite element models of honeycomb test specimen composed of five core cells of identical mass have been constructed, and numerical simulations have been run on PAMCRASH. The dimensions of the sides of core cells as well as the angle betwee...