Modelling and simulation for optimal design of foldable tsunami pod

Abstract

A tsunami is caused by a large coastal earthquake. We devise the foldable tsunami pod on which evacuees can get, when tsunami is approaching. The 3D model for the foldable ellipsoid body is generated by FEM software “LS-PREPOST”. We perform a numerical simulation, and confirm the safety by von Mises equivalent stress and Head Injury Criterion (HIC). As the result of the 1st simulation, it is proved that the initial model is weak to the impact force from rigid wall and obstacles and can be strained in the central part. On the other hand, an occupant hits against the inner side of the wall and can be injured. So, a seat and upper and lower bars are added to the initial model. Von Mises equivalent stress for the modified model is decreased, however is still over the ultimate strength of the 1st simulation. While, HIC value is decreased largely which is much less than the HIC safety level. This is because an occupant isn’t hit by the internal wall for an occupant restraint system. Moreover, we optimize the form and property for a tsunami pod on condition of its mass is minimized by uncoupled analysis. Finally, we confirm the validity of the optimal model by an original condition of coupled analysis.

Keywords

• origami
• tsunami pod
• explicit finite element method (fem)
• arbitrary lagrangian eulerian (ale) method
• head injury criterion(hic)
• optimization