What is the influence of pore sizes on the macroscopic mechanical properties of open-porous cellular materials?

Abstract

The influence of relative density on the macroscopic mechanical properties of open-porous cellular materials is well known within the scientific community [1,2]. However, for those materials that exhibit a rather wide range of the pore-size distributions over the length scale, it is still an open question as to whether the pore sizes influence the bulk properties of the solids. Within a numerical framework, the importance of considering these, along with the strut thickness and relative density was highlighted [3]. In this contribution, we have investigated computationally the effect of the three morphological parameters viz. the relative density, the pore-size distribution, and the pore-wall thickness on the mechanical properties of such open-porous materials. The results obtained demonstrate that while the relative density dictates the mechanical properties of open-porous solids, the effects of pore-sizes, pore-size distributions and pore-wall thickness are not negligible. These effects must be considered, particularly while developing materials showing a poly-disperse porous structure and requiring load-bearing capabilities under finite strains. As an example, the three-dimensional (3-d) porous network of cellulose aerogels is computationally reconstructed and the macroscopic material properties are described and validated against experimental data. References 1. Gibson, L. J., Ashby, M. F., Schajer, G. S., & Robertson, C. I. (1982). The mechanics of two-dimensional cellular materials. Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences 382, 25-42. 2. Gibson, I. J., & Ashby, M. F. (1982). The mechanics of three-dimensional cellular materials. Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences 382, 43-59. 3. Rege, A., Aney, S., & Milow, B. (2021). Influence of pore-size distributions and pore-wall mechanics on the mechanical behavior of cellular solids like aerogels. Physical Review E 103, 043001.