Mechanical behavior and structural complexity of nature-inspired porous materials across scales

Abstract

Porous materials are essential in applications ranging from energy storage to healthcare and play a crucial role in advancing technology and enhancing the quality of life. Understanding the impact of pore morphology across different length scales on mechanical properties is necessary for the efficient design of porous structures and also to ensure the structural integrity of the structures. This study investigates the impact of morphological complexities on the mechanical properties of nature-inspired architected porous materials through pillar compression tests at micro and macro scales. Complexity was determined through the surface fractal analysis of each sample, resulting in idealistic, semi-realistic, and realistic complexity definitions. Results show that semi-realistic and realistic structures exhibit similar stress–strain behavior and micromechanical values, while idealized structures demonstrate lower properties. Moreover, for the same porosity level, loading–unloading loops reveal similar degradation of Young’s modulus across each morphology. However, this impact is significantly influenced by the porosity level and becomes more pronounced at lower strain values for lower porosity. Furthermore, macroscale investigation confirms that semi-realistic and realistic structures exhibit identical behaviors. Additionally, our finite element models demonstrate the power of numerical methods in predicting the behavior of complex pore morphologies. These insights into the structure–property relationships can inform the design of more efficient materials and structures.