feA Simulation: katana slicing wood

Finite Element Analysis

December 2023

The system observed is a katana swing breaking a piece of oak wood. In this system, I would expect the majority of the stress to be shown in the piece of wood rather than the sword. For the system, the entire sword is made out of Plain Carbon Steel, a very common material used in blade works. The wood is treated as oak wood with 12% moisture, as I had to input specific material properties for the simulation to run (ie. Poisson ratio and Young’s Modulus).

For the deformation plots, the model includes the sword as part of the results, which means that the sword experiences more “deformation” than the wood. In actuality, it seems that the sword is only being displaced more since it is the only thing in motion, thus the deformation plots seem to be off. When only comparing the wood to itself, there are differences in the deformation, which makes sense since the wood did get destroyed. The Von-Mises stress plot is interesting since the wood undergoes a varied amount of stress to the point where the simulation notes small parts of the wood experiencing stresses up to 2.8 x 10^10 Pa. Considering the sword is traveling at a velocity of 800 m/s (1789.55 mph), I would say these large values in stress are reasonable. 

One thing that may have changed the results to not be accurate is how I set the simulation. I don’t think I correctly set up the body interactions and the connections of the elements in the system to accurately represent a sword cutting through wood, which can seriously affect the interpretations of the results.

I played around a lot with different settings and tried to cross-reference different sources I found online and what was available in the canvas. Saying that this was the first time using ANSYS, let alone explicit dynamics, I think I learned a lot trying to figure out how to use ANSYS.