This paper introduces a purely heuristic topology optimization framework to improve specific energy absorption for thin-walled, extruded lattice structures. The optimizes the cross section design by iteratively updating wall thicknesses. main novelty of work is two novel thickness update schemes we proposed. first scheme direct statement homogenization wall-wise absorption, while other based on...

Energy absorption capability of thin-walled structures with various cross sections has been considered by researchers up to now. These structures as energy absorbers are used widely in different industries such as automotive and aerospace and protect passengers and goods against impact. In this paper, mechanical behavior of thin-walled aluminum tubes with and without polyurethane foam filler su...

eart pressure problems are encountered in retaining walls, bulkheads, sheeting and bracing in cuts,culverts, tunnels, and cofferdams. in many cases, the lateral pressure is determined by use of classical earth pressure theories, such as coulomb's, where the equilibrium conditions of a failure wedge of soil is considered. excessive dynamic lateral earth pressure on retaining structures resu...

Patterns formed by nano/microparticles in colloidal systems are of great interest and importance from both scientific technological points view. Magnetic colloids particularly interesting since the structures magnetic particles can be quite easily controlled external fields. In this study, we investigate growth process clusters paramagnetic microparticles a fluctuating field composed direct cur...

The influence of wall elasticity on the response of a Helmholtz resonator is examined by analyzing the canonical case of a thin elastic spherical shell with a circular aperture subject o plane wave excitation. By neglecting the thickness of the wall and representing the elasticity via a "thin shell" theory the problem is reduced to one of solving an integral equation over the aperture for the p...

Within D=4 N=1 supergravity theory we obtain an effective theory of the thin wall limit for a flat domain wall configuration, interpolating between isolated supersymmetric extrema of the matter potential. We focus on the Z2 symmetric flat wall and derive the supersymmetric effective action both in the bulk and on the wall; in the thin wall limit the scalar field, forming the wall, is frozen, an...

Several vibro-acoustic models for either single wall or multi-layer constructions are based on classical plate and first order shear deformation theories. The equivalent condensed employ the thin model to extract dynamic mechanical properties of system considering only flexural motions structure under investigation. Since these do not account compressional symmetric motion structure, both thick...

Transport of DNA across bacterial membranes involves complex DNA uptake systems. In Gram-positive bacteria, the DNA uptake machinery shares fundamental similarities with type IV pili and type II secretion systems. Although dedicated pilus structures, such as type IV pili in Gram-negative bacteria, are necessary for efficient DNA uptake, the role of similar structures in Gram-positive bacteria i...

Ferroelectric domain structures of (001)SrBi2Nb2O9 epitaxial films, investigated using both transmission electron microscopy and phase-field simulations, are reported. Experiment and numerical simulation both reveal that the domain structures consist of irregularly shaped domains with curved domain walls. It is shown that the elastic contribution to domain structures can be neglected in SrBi2Nb...