Reinforced Concrete Load-bearing Column In The Explosion Under Impact Loading, Dynamic Analysis

Although peace and development are the mainstream of modern society, nowadays terrorist activities continue to occur. Since the targets of terrorism tend to be industrial factories and civilian buildings, it not only is harmful to citizens and the property security, but also results in a great impact on social culture. Therefore, how to improve the resistance of explosion for reinforced concrete structure has become one of the most important fields for academic research both in China and abroad.Column is an essential member of reinforced concrete construction with regards to mechanical analysis and security. It connects stories, transfers all kinds of forces, combines the whole structure with the foundation and maintains the stability and security of the structure. If the columns are damaged by blast and impact loads, the structure cannot function properly or, even worse, collapses continuously. This paper, based on the frame structure of VISA Office Building of a consulate compound, adopts theoretical analysis and numerical simulation for the damages caused by blast and impact loads on reinforced concrete columns.Firstly, this paper introduces the basic theories of explosion and explosives. Based on the three laws in explosion mechanics (conservation of mass, conservation of momentum and conservation of energy), recount the principle of action of explosion, including the theory of explosive wave, similitude law of explosion, parameter calculation of explosion shock wave, the damage theory of explosion and so on.Secondly, this paper introduces strain rate's impacts on the property of steel bars and concrete with the compression strength and tension strength of blast and impact loads and a very limited amount of time.Thirdly, the finite element software ANSYS/LS-DYNA is used to simulate the typical reinforced concrete column. The process is composed of entitative model simplification, elements and material model, meshing size controlling, boundary condition controlling, load calculation and adding, etc. Meanwhile, the results, including stress types, strain and displacement of time-history curve for node and element in different places, are analyzed. To ensure the accuracy of the results, transverse displacement in the middle section is contrasted with the test data from a researcher.Fourthly, conclusions are reached by contrasting parameters (scale distance, reinforcement ratio, stirrup spacing, constraint on the top of reinforced concrete columns) and their influence on resistance of explosion for reinforced concrete columns.Theoretical analysis and numerical simulation for resistance of explosion of reinforced concrete columns are applied in this paper. Hopefully the preliminary conclusions can be informative for future designs and researches in the field of resistance of explosion for reinforced concrete structure.