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.

Fragmentation and hazard analysis of brittle materials under far-field blast loading

“…Sung et al (2020) used a single degree of freedom (SDOF) model to calculate the average fragment velocity of a reinforced concrete (RC) structure. They employ a similar experimental setup to Xu and Lu (2006) to validate their model.…”

“…Ultimately, the energy imparted to the system drives fragment generation and results in fragments with significant kinetic energy. Lu and Xu (2007) and Sung et al (2020) use the impulse as an effective way to calculate the energy of the system. Both Dennis et al (2002) and Eamon et al (2004) noted that the negative phase loading had an impact on CMU wall behavior.…”

“…Xu and Lu (2006), Lu and Xu (2007), and Sung et al (2020) use an equation from Biggs (1964) to calculate the energy imparted to a system from an impulse loadwhere I s is the specific impulse and M wall is the mass of the wall being loaded. The difference between peak impulse and the impulse at the end of the negative pressure phase can be significant.…”