Numerical Simulation on Damage and Failure of Metro Structure under Penetration and Explosion Effects

Taking Shuitun North Road Station of Jinan Rail Transit Line 7 as an example, a numerical simulation study was conducted to investigate the structural damage and failure effects of the metro structure based on the fluid-structure couple and full restart algorithm in LS-DYNA software. This study focused on two scenaries: projectile penetration followed by an explosion from outside to inside, and the inner explosion of a large equivalent TNT charge. Firstly, the accuracy of the numerical simulation and the selection of material model parameters were validated through the penetration followed by explosion test. Then, three cases of two-dimensional numerical model for penetration followed by explosion from outside to inside and three cases of three-dimensional numerical models for internal explosion were established. The damage mode of the metro structure and the damage condition for personnel and auxiliary components were analyzed. The simulation results demonstrate that the failure mode of the metro structure subjected to projectile penetration followed by explosion was localized damage. When the explosion occurs inside the metro structure, the peak of overpressure decays faster in the area close to explosion and slower in the middle and far area of the explosion. The present research results can provide a reference for further studies on the radial and normal shock wave propagation attenuation laws of the metro structure subjected to internal explosion.