Failure modes of concrete structure under penetration and explosion

Based on the large caliber launch platform, the experiment of 155 mm high explosive bomb damaging steel fiber reinforced concrete structure was carried out, and the damage feature of the structure being struck at different positions was obtained. Combined with LS-DYNA numerical simulation, the damage effects of steel fiber reinforced concrete structures under different impact positions and different hit speeds are analyzed, and the damage process and failure modes of steel fiber reinforced concrete structures under the combined action of penetration and explosion are discussed. The results show that under the action of 155 mm high explosive bomb, the roof and side wall of steel fiber reinforced concrete structure have a relatively light explosion pit damage, and the front wall without reinforcement has a serious explosion collapse damage. SPG (smooth particle Galerkin method)-structured ALE (arbitrary Lagrange-Euler) (S-ALE) fluid-structure coupling algorithm can effectively predict the damage development process and failure mode of reinforced concrete structures under the combined action of penetration and explosion. The acceleration time-history curve of large caliber projectile penetrating finite boundary targets is characterized by sudden increase and sudden decrease of single peak, and the projectile velocity is characterized by rapid decrease at first and then slow decrease. The main failure modes of the target under the explosion based on penetration damage are massive collapse and crack growth of concrete blocks. With the increase of penetration speed, the damage caused by explosion develops from local damage to overall failure of the structure. In the concrete crushing zone, the reinforcement perpendicular to the projectile body will yield under the penetration effect, and the reinforcement at the top and bottom of the plate will yield under the explosion.