The effect of pore-wall morphology on the scaling exponents for open-porous materials

Abstract

Open-porous materials such as aerogels are characterized by a network of pores which have a significant influence on the material properties. For example, in case of cellular materials, the influence of the pore sizes and the pore-size distributions has been investigated, both theoretically and computationally [1,2]. In these approaches, the pore walls were modelled as beams with constant cross-section. While this assumption is sufficient for cellular materials with fibrillar morphology, it seems too ideal for particle-aggregated materials which possess a pore-wall structure similar to a chain of pearls. It has been observed that approximating the pore-wall of such materials with a constant cross-section can lead to serious miscalculations of their mechanical behavior [3]. Thus, the effect of the pore-wall morphology is studied further using the Gibson and Ashby power law relation [4, 5] which correlates the relative density of the material with its Young’s Modulus. In this contribution, unit cells with different pore-wall structures are created. These structures are simulated under compressive loads to calculate the respective scaling exponents. It has been shown that while the pore-wall morphology plays an important role in the prediction of the failure of the material, its influence on the scaling exponents is not comparable.

References

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