Dynamic behaviour of auxetic gradient composite hexagonal honeycombs

Due to the complex nature of such composite structures, an understanding of the guided wave propagation mechanism in honeycomb composite panels with different frequencies inherently imposes many challenges. In this paper, a numerical simulation is first conducted to investigate the wave propagation mechanism in honeycomb sandwich structures using piezoelectric actuators/sensors. In contrast to most of the previous work, elastic wave responses based on the real geometry of the honeycomb core are obtained by using the finite element method (FEM). Based on the simulation, the global guided waves in the composite can be observed when the loading frequency is low and the leaky guided waves in the skin panel are found when the loading frequency is sufficiently high. The applicability of the homogenization technique for a celled core is discussed. The effects of cell geometry on the wave propagation are also demonstrated. Experimental testing is finally conducted to validate the results of numerical simulation and very good agreement is observed. Specifically, some guided wave propagation characteristics such as group velocity dispersion and mode tuning capabilities with the presence of a honeycomb core are discussed.

https://iopscience.iop.org/article/10.1088/0964-1726/18/12/125007/pdf

Guided wave propagation in honeycomb sandwich structures using a piezoelectric actuator/sensor system

This article concludes some of the important observation regarding quasi-static and dynamic crushing response of honeycomb structure carried out by authors and addressed in the literature. ...

Crushing behavior of honeycomb structure: a review

This study develops a numerical framework for the analysis of the sensitivity of real potting shape with respect to the position of the insert centre inside the cell geometry. An investigation using a finite element analysis to evaluate the effect on the position of ‘through-the-thickness’ inserts type in all aluminium honeycomb sandwich panels for spacecraft applications under tensile load. Twelve positions are presented and analysed. The distribution of stress due to the critical load is also determined in the core and face sheet for different potting shape and various insert positions. The results are very satisfactory and provide adequate shear stress distributions in honeycomb core between theoretical and various positions of the finite element models. The results show also how the pull-out strength of inserts in honeycomb/cored sandwich panels affected by the placing of the insert relative to the local honeycomb structure and the shape of the potting geometry which has a significant effect on the sandwich honeycomb panel.

Effect of position of tension-loaded inserts on honeycomb panels used for space applications

In order to further improve the accuracy of the equivalent models of the trapezoidal corrugated core, a 3D homogenization method based on a representative unit cell (RUC) has been developed...

Numerical static and dynamic analyses of improved equivalent models for corrugated sandwich structures

In this paper a mathematical model based on a multi-scale asymptotic technique for the dynamic description of honeycomb structures is presented. The technique is used to evaluate an equivalent orthotropic model of the honeycomb. The derivation is based on an asymptotic analysis for periodic structures developed by Bensoussan, Lions and Papanicolaou. The method is totally general; in fact, it is applied to Cauchy’s partial differential equations that describes the dynamics of an elastic material. Elastic and density characteristics are determined in terms of the cell geometry and material of the honeycomb. A numerical validation is carried out by using a finite-element modeling (FEM) numerical simulation.

Luca Guj

Papers

Dynamic modeling of honeycomb sandwich panel

Characterization of the Stiffness Properties of Honeycomb Core Structures via an Homogenization Technique