Numerical Exploration On Dynamic Performance Of Reinforced Concrete Members Under Explosive Load

The progressive collapses of building structures under explosive load are often caused by the failure of the key members. The anti-knock performance of key members can affect the security of overall structure directly. Study on dynamic performance of key members in structure under explosive load to enhance the anti-knock ability can enhance the security level of the overall structure effectively. At present,study on dynamic performance of reinforced concrete members under explosive load is limited, so this article is located at exploring the main influence factors of dynamic performance of reinforced concrete members under explosive load. The main aspects of research work are as follows:(1) The merits and drawbacks of different research methods of dynamic performance of reinforced concrete members under explosive load are compared. The analytic software LS-DYNA based on dynamic finite element method is chosen to explore the dynamic performance of reinforced concrete members under explosive load, the basic principles of dynamic finite element method and the dynamic constitutive models of materials are introduced.(2) Based on the existing test and material characteristic, numerical model of dynamic response of reinforced concrete column under explosive load is designed and computed by using the explicit dynamic analytic software LS-DYNA. The results from numerical simulation and measured data in existing test are compared to verify the accuracy of numerical model.(3) With the maximal dynamic deformation and the maximal internal force of material as standards of dynamic performance of reinforced concrete members under explosive load, the influence of shapes of cross section, boundary conditions, span-depth ratio, strength of materials, and axial compression ratio are compared by the verified numerical model respectively. The purpose is to obtain some guided rules for actual works.(4) Based on the equalities of peak detonation pressure and peak detonation impulse, simplified calculation formulas of detonation pressure distribution in the time-space coordinates on front surface of members are suggested with the help of empirical formulas. Comparison of dynamic performance of reinforced concrete members in the numerical model and simplified calculation model of detonation pressure is made to verify the reliability of simplified calculation formulas of detonation pressure.At last, the main research work is generalized and summarized, and further studies on some topics are suggested.