The effect of pore sizes on the elastic behaviour of open-porous cellular materials

Abstract

The influence of the pore structure characteristics in open-porous cellular materials on their macroscopic elastic behaviour is investigated by considering three important microstructural features viz. the relative density, the pore-size distribution, and the pore-wall thickness. To this end, a microstructure-informed modelling approach is presented, where all elements of the three-dimensional (3-d) pore structure can be controlled effectively. The results show that while density does dictate the mechanical properties of open-porous solids, the effects of the pore-wall thickness and the pore-size distribution are not negligible and must be considered while developing such materials, in particular those that exhibit a poly-disperse nature and require load-bearing capabilities under finite strains.

The Effect of Particle Necks on the Mechanical Properties of Aerogels

“…For instance, Young's modulus E should vary with the relative density in a simple power law fashion E ∝ ρ 2 and the plastic rupture strength σ cr should depend on the density in a similar way, namely σ cr ∝ ρ 3/2 . While recent investigations have asserted the importance of the pore-size distributions and pore-wall morphology, alongside the relative density, in dictating the mechanical properties of such materials [2], the scaling relations still hold true for a vast majority of open-porous materials. This is a consequence of the models proposed by Gibson and Ashby, which work fine because many porous materials exhibit a cellular structure with walls of constant cross section, and in open-porous materials the edges of the pores, the struts, and beams can be described as smooth quadratic bars or cylinders.…”

“…In aerogels, the pore sizes range from a few ten nanometers to even micrometers, and the struts are, for instance, in the case of silica and Resorcinol-Formaldehyde (RF)-aerogels, better described as a pearl-necklace structure as shown with a lot of scanning electron micrograph (SEM) pictures in the book of Ratke and Gurikov [3]. While recent models have tackled the subject of pore-size or cell-size distributions in such materials [2,4], the effect of network connectivity and the effect of this pearl-necklace-like morphology remains less addressed. Some newer models described the mechanical properties of aerogels with twodimensional (2D) or 3D pore model of constant cross-section [5][6][7] taking also into account network defects, like dead ends, dangling beams, and struts.…”

A Perspective on Methods to Computationally Design the Morphology of Aerogels

“…It was recently illustrated that it is not only the density, but also the pore sizes and the pore‐wall morphology that dictate the mechanical properties in aerogels. [ 97 ] This was shown by applying the above‐mentioned radical Voronoi models, thus demonstrating the capabilities of the modeling approach to (a) design aerogel networks and (b) investigate the structure‐property relations.…”

Acoustic Properties of Aerogels: Current Status and Prospects

“…[46] Figure 5b illustrates the cases of aerogels from different polysaccharide sources. [24] The reason of these differences is different network connectivity, pores size, and pore wall morphology (see, for example, [47] ). Low density, fine morphology, and high specific surface area make all types of aerogels very promising for various applications.…”

“…[ 46 ] Figure 5b illustrates the cases of aerogels from different polysaccharide sources. [ 24 ] The reason of these differences is different network connectivity, pores size, and pore wall morphology (see, for example, [ 47 ] ).…”