Failure mode analysis and dynamic response prediction of fully confined reinforced concrete slabs under blast loading

Abstract

With the development of human society, various accidental explosions and terrorist attacks have occurred frequently, posing a great threat to the safety of building structures. In order to improve the safety of building structure, the finite element model of reinforced concrete slab was established by ANSYS/LS-DYNA finite element analysis software. By comparing with the experimental results, the accuracy of the established finite element model was verified, and the failure modes of reinforced concrete slab under different scaled distances were analyzed. The effects of three damage factors: concrete compressive strength, protective layer thickness and reinforcement ratio on the dynamic response of the slab were analyzed. Based on the Π theory of dimensional analysis, the dimensionless relationship between the peak displacement of the mid-span of the plate and the scaled distance of the explosion is obtained. On the basis of a large number of numerical simulation results, the dimensionless relationship for quickly predicting the dynamic response of the plate is summarized. The results show that with the increase of scaled distance, the failure mode of the plate will gradually change from brittle shear failure to plastic bending failure. Increasing the compressive strength and reinforcement ratio of concrete and reducing the thickness of the protective layer can reduce the peak displacement of the mid-span of the slab and improve the anti-explosion performance of the slab. It is verified that the proposed dimensionless prediction relationship can better predict the dynamic response of reinforced concrete slabs at different scaled distances, so as to provide some reference for the field of structural anti-explosion.