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 1. 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. 2. Aney, S., & Rege, A. (2022). The effect of pore sizes on the elastic behaviour of open-porous cellular materials. Mathematics and Mechanics of Solids, 10812865221124142. 3. Rege, A., Aney, S., & Ratke, L. (2022). Impact of pearl-necklace-like skeleton on pore sizes and mechanical properties of porous materials: A theoretical view. AIP Advances, 12(10), 105108. 4. 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. 5. 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