Prediction of average debris launch velocity from a reinforced concrete structure based on SDOF system

Abstract

This study presents a physics-based model for debris launch velocity prediction of a reinforced concrete (RC) structure subjected to a blast load. The model is basically derived from energy conservation equation. Especially, a resistance-deflection relationship for the structural single degree of freedom (SDOF) system is newly considered to evaluate the energy consumed by the damage and fragmentation of the RC structure. By applying the resistance-deflection relationship, the proposed model can consider the interactions between reinforcing bars and concrete. Moreover, since the resistance-deflection curve is evaluated considering various structural properties as well as boundary conditions, the proposed model can be flexibly utilized compared to conventional approaches. In order to confirm the performance of the proposed model, a comparative study was carried out against benchmark experiments on closed concrete box structures under an internal blast. From the comparative study, it was shown that the debris launch velocities estimated from the proposed model had a good agreement with the test results compared with the other models.