Investigation On Anti-explosion Performance Of Reinforced Concrete Structure Under The Close-in Explosion

As the rapid development of the economy and globalization, industrial production problems and the man-made blast events become common occurrence, coupled with a series of terrorist attacks which happened in the recent years. The blast-resistant design of significant building structures has aroused the wide concerns. Currently, the most structures being built by reinforced concrete play an important role in economic and social functions and military purposes. Therefore, it is very significant to conduct the investigation on anti-explosion performance of reinforced concrete structures under close-in explosion, so as to take rational measures to minimize the potential loss induced by the unforeseen disaster and protect the security of human life and property.Based on extensive comparison of the constitutive models suitable for simulation of concrete and reinforced bars and validation of blast load in free air, systematic and intensive study on the anti-explosion performance of reinforced concrete structures is carried out. The main work in this paper can be summarized into following several aspects.(1) In the analysis of a structure subjected to blast load, the primary problem is to determine the magnitude and acting mode of the blast load. To examine the influencing factors, a series of blast load simulations in free air have been carried out, different mesh sizes are explored and the trend of convergence of the blast parameters is scrutinized. The simulation results are benchmarked against the empirical formula and data available in TM5-1300, and the corresponding method to improve the simulation accuracy is proposed.(2) Various kinds of concrete material models with strain-rate dependence are presented, the limitation and applicability of these models are reviewed, and dynamic constitutive models of reinforcing bar and concrete under high strain rate loading are established.(3) Based on the user subroutine of AUTODYN software, the concrete material model developed by Malvar is included into the software, which may take into account the effects of damage in tension and compression, as well as strain rate. Its feasibility and effectiveness are tested in the following numerical simulation.(4) Using the hydrocode AUTODYN, the numerical models of RC slab, column and frame structures are established to analyze the dynamic response and failure mode of structural components under different explosive charges, several meaningful conclusions are drew, which may provide the anti-explosion design with theoretical basis and references.