Innovative honeycomb-based structures have been paid substantial attention in recent years due to their superb mechanical performances and specific functions. The presented study made acomprehensive overview on the development of the innovative honeycomb-based structures in the past two decades, including filled-type, embedded, tandem, hierarchical, auxetics with Negative Poisson's Ratio (NPR), etc. Mechanical performances of these structures were commented with advantages and disadvantages, related on their geometric configurations, mechanical performance and dynamic response, respectively. The challenges as well as future directions were also analyzed. The achievements provide significant guidelines in designing of new generation light-weight honeycomb-based structures.

Recent advances in novel metallic honeycomb structure

Geometric configurations in nature could be mimicked in order to develop novel materials and structures with desirable properties. Lots of bio-inspired configurations had been introduced to tubal structures in promoting the energy-absorption performance of thin-walled structures. Nevertheless, these existing studies largely focused on hierarchical hexagonal honeycombs, and the bio-inspired hierarchical circular thin-walled structures under the out-of-plane crushing loads had not been well studied experimentally, numerically and analytically for energy absorption to date. In this study, the bionic honeycomb tubular nested structure (BHTNS) was first inspired by the micro-architecture of bamboo vascular bundles, which could be mimicked by connecting a central circular tube to other six circular tubes in a hexagonal arrangement, regardless of size or choice of materials. The energy-absorption characteristics of BHTNS under axial crushing were systematically studied by drop-weight experiment, numerical simulation, and theoretical analysis. Dynamic drop-weight impact experiments were conducted and the results showed that the specific energy absorption ( S E A ) of BHTNS was as high as 29.3 J/g. Furthermore, the parametric numerical simulation revealed the influence of diverse mean diameter D of the circular tube and length L of the junction plate on the energy-absorption characteristics. Finally, a theoretical model was also developed to predict the mean crush force P m , which was in good agreement with the numerical simulation. This work could provide a reference for an energy-absorber design with high efficiency.

Energy-absorption characteristics of a bionic honeycomb tubular nested structure inspired by bamboo under axial crushing

Drop-weight impact behavior of honeycomb sandwich panels under a spherical impactor

The paper investigated the dynamic impact response and characteristics of aluminum honeycomb filled with EPP foam (Expanded polypropylene) experimentally and numerically. It was found that the initial peak strength and mean strength of the filled honeycomb were improved significantly attributable to the interaction effect between the aluminum honeycomb and the foam, but the specific energy absorption (SEA) decreased. For the filled specimens with the same foam density, the initial peak strength, mean strength and SEA increased with the increase in impact velocity. Compared with the characteristics in the static compression test, the initial peak strength in the dynamic impact test increased, whereas the mean strength and SEA decreased. The study showed that EPP foam filling was effective to improve the impact characteristics of the bare aluminum honeycomb. Numerical simulation for the dynamic impact of filled honeycombs was also explored. It accurately reproduced the deformation process and addressed the interaction between the wall and EPP foam. By comparison of the properties in different filling types, it showed the single-cell filling was a good choice to improve the load resistance while using the least filling material.

Dynamic impact response of aluminum honeycombs filled with Expanded Polypropylene foam

Energy absorption of thin-walled tubes enhanced by lattice structures

Crashworthiness parameters of aluminum hexagonal honeycomb structures under impact loads are investigated by using finite element methods and conducting experiments. To validate the finite element models, numerical results are compared with experimental measurements and theoretical results reported in literature. In numerical simulations of honeycomb structures, out-of-plane loads are considered while the aluminum foil thickness, cell side size, cell expanding angle, impact velocity and mass are varying, and dynamic behavior and crashworthiness parameters are examined. It is observed that there are good agreements between numerical, experimental and theoretical results. Numerical simulations predict that crashworthiness parameters depend on cell specification and foil thickness of the honeycomb structure and are independent of impact mass and velocity.

Numerical and experimental study of crashworthiness parameters of honeycomb structures

A design approach for a crash energy management (CEM) system for a N13-type railway passenger car used by the Turkish State Railway Company is developed in this paper. The components of the CEM sys...

Development of a design for a crash energy management system for use in a railway passenger car

This paper presents a study on the development of a side buffer to absorb the impact energy of colliding railcars. Buffers are essential elements for improving the traveling comfort of passengers a...

Ahmad Partovi Meran

Papers

Numerical and experimental study of crashworthiness parameters of honeycomb structures

Development of a design for a crash energy management system for use in a railway passenger car

Design and analysis of a hydraulic–elastic railcar buffer: