Quantifying blast damage and failure mode transition in reinforced concrete columns with a dimensionless model

Various accidental explosions and terrorist attacks have occurred frequently, posing a huge threat to the safety of building structures. To enhance the safety of building structures, the finite element model of a reinforced concrete column was established by ANSYS / LS-DYNA finite element analysis software. By comparing with the experimental results, the accuracy of the finite element model was verified, and the failure mode of reinforced concrete columns under different scaled distances was analyzed. The effects of four damage factors: charge weight, axial load ratio(ALR), concrete compressive strength, and stirrup ratio on the dynamic response of column damage were analyzed. Based on the dimensional analysis Π theory, the dimensionless relationship between the damage coefficient of the column based on the residual axial bearing capacity and the explosion scaled distance is obtained. Based on a large number of numerical simulation results, a damage assessment method for reinforced concrete columns subjected to explosion loads is proposed, utilizing dimensional analysis theory. The results show that with the increase of scaled distance, the failure mode of the column will gradually change from brittle shear failure to plastic bending failure. Increasing the axial load ratio, concrete compressive strength and, stirrup ratio, and reducing the charge weight can reduce the damage to the column and improve the blast-resistant performance of the column. It is verified that the proposed dimensionless prediction relationship can better predict the damage degree of reinforced concrete columns at different scaled distances, to provide some reference for the field of structural blast-resistant.