Influence of U-shaped stiffeners on the blast-resistance performance of steel plates

Abstract

U-shaped stiffeners stiffened plates subjected to blast loads were investigated in the study. Field blast experiments were performed, and a fine finite element (FE) model was constructed and validated by the experimental results. Four damage modes of the stiffened plates were discovered by parametric analysis: (I) large plastic deformation, (II) partial steel plate damage or stiffener rupture, (III) tensile tearing at the boundary, and (IV) shear failure. In this study, the influence of U-shaped stiffeners on the blast-resistance performance of steel plates was investigated. The damage modes, energy absorption, and deflection responses of the stiffened plates were investigated to understand the influence of U-shaped stiffeners. The damage modes could be changed by the stiffeners, and were significantly related to stiffener characteristics. When stiffeners of the same thickness were used, the ratio of energy absorption of the steel plate to stiffeners (QSP/QST) decreased as the number and size of stiffeners increased. However, when the same equivalent thickness plates were adopted, the QSP/QST may be remained stable while a sufficient number and size of stiffeners were used. The average residual displacement (Daverage) and nominal support rotation angle (α) decreased linearly with the number and size of stiffeners, and increased when the same thickness stiffeners were used. While plates of the same equivalent thickness were used, the stiffeners could sometimes effectively decrease the Daverage and α of the stiffened plates. However, when large deformation occurred, the Daverage and α of the stiffened plates were comparable to those of bare steel plates with the same equivalent thickness.