Simulation experiments on the effective in-plane compliance of the honeycomb materials

Abstract

A statistical simulation model is presented to compute the effective in-plane compliance matrices of the honeycomb materials. The present model is explained in three stages: the micromechanical model, simulation experiments under external loading and boundary conditions, and the analysis of the experiment results. In the micromechanical model, mean values of the geometrical and mechanical parameters and variations related to cell wall height and thickness are used in order to mimic the actual materials in the virtual environment. Simulation experiments are performed on these replicated materials under the assumption of linear elasticity. The effect of solution artefacts near the boundary domain is controlled by defining a measurement domain where the strain and stress fields are assumed to be constant. The simulation results for this domain are processed with transformation and the least squares minimization to obtain the effective in-plane elastic parameters. In this context, two case studies are conducted. The first case study aims at understanding the influences of the cell geometry and aforementioned variations on the linear elastic material behavior. Meanwhile, the scope of the second case study is to validate the proposed model by comparing the simulation results with the measurements conducted on Nomex ® honeycomb materials by the authors.

The flatwise compressive properties of Nomex honeycomb core with debonding imperfections in the double cell wall

“…The first folding completes as the compressive displacement is about 1.8 mm. The out-of-plane stress components, σ 33 , σ 13 …”

“…There are two layers of aramid paper in a double cell wall bonded together through adhesive, but one layer of phenolic resin on the surfaces of each cell wall [12][13][14][15]. However, in reality, honeycomb structure is neither perfect in geometry nor free of imperfections.…”

Mechanical properties of additively manufactured octagonal honeycombs

“…Several experimental [14][15][16][17][18][19][20][21] and numerical [22][23][24][25][26][27] works have been published on the inplane deformation of honeycombs. Hexagonal shape is the most widely studied geometry among the honeycombs.…”

A fiber network model to understand the effects of fiber length and height on the deformation of fibrous materials

“…Fiber networks, in which the natural or artificial fibers are randomly or directionally aligned and bonded together through a chemical, mechanical and/or thermal processes, form the structural foundations for various engineering materials. Some of these include nonwoven fabrics used in hygiene products, car panels, building and roof coverings, waddings and geotextiles; fiber mats and filters used in electromagnetic shielding and fuel cell gas diffusion layers; sintered metallic fiber networks for prosthetics and metalmatrix composite applications; felted or layered wood fiber networks used in paper and packaging products [1][2][3][4][5][6]. Their deformation and failure characteristics are dependent on the geometrical and spatial properties of constituents [7][8][9].…”