Experimental, numerical, and dimensionless analysis studies for the structural response of steel plates under repeated internal blasts

Internal blasts are more destructive than air blasts due to the multiple reflection overlays of explosive shock waves in the confined space. This paper conducts experimental, numerical, and dimensionless analysis studies for the structural response of steel plates subjected to repeated confined blasts. A couple of experiments, including different charge masses, stand-off distances, and blast number, are conducted to investigate the response of steel plates to a confined blast device. Experimental results show that the deflection of the target plate close to the blast point was smaller. The progressive deflection is decreased for repeated blasts. Then, a numerical simulation model is built further to investigate the structural response characteristics for repeated confined blasts. Finally, an empirical model is proposed to predict the central permanent displacement of the target plate under repeated confined blasts. This model considers the material and structure parameters of the target plates, the charge parameters, the local properties of the blast loading, and the influence of the venting. Results show that this model can predict the midpoint displacements of the target plates well.