IT in Industry

This paper presents the design of a deployable and foldable tsunami pod for older and disabled people who cannot run to higher grounds during a tsunami attack. In our design, we adopt an ellipsoid structure and use finite element method (FEM) to model the structure. Then, we conduct numerical simulation and confirm the safety based on the von Mises equivalent value and the Head Injury Criterion (HIC). As the result of the first simulation, it is proved that the initial model referring to the commercially available tsunami shelters is weak against the impact force from rigid walls and obstacles and can be strained in the central part. And also, the occupant might hit against the internal wall and get injured. Therefore, a seat and upper and lower bars are added to the initial model. As a result of the second simulation, the von Mises equivalent value for the modified model is decreased, but still above that of the first simulation. The HIC value is decreased largely and is much less than the HIC safety level. This is because the occupant restraint system will prevent the occupant from hitting the internal wall of the pod. Moreover, we optimize the structure for the tsunami pod by minimizing its weight. Finally, we confirm the validity of the optimal model in the original condition of fluid-structure coupling analysis. Keywords— tsunami; von Mises equivalent stress; explicit finite element method; arbitrary Lagrangian Eulerian method; head injury criterion; optimization; origami