A Study of Mapping Technique for Air Blast Modeling

Since LS-DYNA® v971 r4, a new 2D ALE method with an associated Mapping technique is available. Mapping enables the decomposition of a calculation in several steps: at the end of a 2D ALE calculation, data from the last cycle can be mapped into another 2D or 3D mesh. Several finite element studies of Air Blast were modeled to evaluate efficiency and potential of this new LS-DYNA feature. First, an influence study was performed to evaluate the impact of the mesh characteristic length variation during the Mapping on shock wave both on pressure peaks and impulses. The analysis is focused on the evaluation of the loss due to the Mapping technique. Then, a comparison with experimental data on a simple 2D study of air blast using Mapping technique was performed. The very good precision obtained with the 2D ALE method and its ability to represent air blast phenomena will be shown.