Difference Analysis of Different Explosion Load Simulation Methods Based on LS-DYNA

Abstract

LS-DYNA provides a variety of different explosion load simulation methods, which are widely used in the field of explosion shock. Compared with the direct application of explosion load on the structural surface, the simulation method of establishing the air domain is more complex, but it can reproduce the evolution process of the explosion flow field and consider the interaction between the shock wave and the structure. The simulation results are more consistent with the actual situation. In this paper, the four commonly used explosion load simulation methods in LS-DYNA software are compared and analyzed, and the sensitivity analysis of grid size is carried out. The differences in the results of the four explosion load simulation methods under typical explosion conditions are compared and analyzed from the aspects of explosion shock wave waveform, arrival time, overpressure peak and specific impulse. The analysis results show that the proportional detonation distance of 0.8 m/kg1/3 is the boundary point of grid sensitivity ; under the same grid size, different explosion load simulation methods have little effect on shock wave arrival time, but have obvious influence on overpressure peak value and specific impulse. It is critical to reasonably select the termination time of the low-dimensional model when using the mapping method ; method 1 and method 2 are preferred for simulation without considering the computational cost or small model size. When the model is large, method 3 and method 4 should be preferred to improve the computational efficiency.