Structural study of the behavior of Tanjiro's katana: Strength, fragility, and functionality

Abstract

This study analyzes the structural behavior of a fictional katana through artificial intelligence-assisted simulations and Finite Element Analysis (FEA), with the objective of evaluating the physical plausibility of three extreme scenarios depicted in the Kimetsu no Yaiba series: cutting through a stone-like material, sustaining blade combustion, and undergoing a clean fracture caused by a filament. A three-dimensional model of the sword was developed, considering an AISI 5160 steel blade and an oak wood handle, while dynamic and thermal loads, as well as fracture mechanics criteria, were applied. The results indicate that the stress and strain levels generated during the impact events significantly exceed the elastic and ultimate strength limits of the material, resulting in immediate structural failure. Furthermore, prolonged exposure to elevated temperatures was found to compromise the mechanical integrity of the blade, while the pressure required to sever it using a filament surpasses the capabilities of existing materials and real-world systems. Overall, the analysis confirms the physical infeasibility of the feats represented in the series and demonstrates the value of Finite Element Analysis as a powerful tool for assessing structural limits in mechanical systems, even within fictional contexts.