Dynamic Response Analysis Of Reinforced Concrete Wall Under Explosive And Impact Loads

Terrorism occurs frequently although nowdays peace and development are the mainstream of modern society. The explosion events occurs more frenquently than other terrorist events. The terrorism have threaten the peace of the whole world, so it is the main factor of endanger the security of many countries. Besides explosion brought by the terrorism, there are other explosive accidents, such as explosion of gas, blast of industrial production. Research on the theory and the technology protecting the structure from the blast is a practical and urgent subject. The dynamic response analysis of structure under explosive and impact loads is an important field. Nowadays, the theory on resisting explosive load for structure is incomplete, so it needs further discussion and study.Dynamic response analysis of reinforced concrete wall under explosive or impact loads were investigated by theoretical method and numerical method in this paper. The largest dynamic displacement of reinforced concrete wall was deduced by adopting the parameter of bidirectional slab with the four sides fixation based on approximately design method of equivalent single-degree-of-freedom system; The dynamic response of the reinforced concrete wall under explosive or impact loads is simulated using the software ANSYS-LS-DYNA, The 3-D model of the reinforced concrete wall was set up in ANSYS-LS-DYNA. The curves of largest displacement versus time of the wall with four sides fixting were obtained from the results of numerical simulation. The numerical results agree well with that of the theoretical method. It indicates that the theory of bidirectional slab with the four sides fixation applying to analysis of the wall is accurate and reasonable. And the parameters of the material model 96 are reliable in the finite element model. In the end, by taking advantage of the numerical simulation, a lot of factors affecting the dynamic response of wall are analyzed, such as boundary conditions, ratio of reinforcement, thickness of wall, strength of concrete, and peak value and duration of the explosive load etc. Some conclusions can be obtained as follows:1. Basing on approximately design method of equivalent single-degree-of-freedom system, dynamic response of reinforced concrete wall under right-angled triangle form of explosive or impact loads are analyzed by adopting the parameter of bidirectional slab with the four sides fixation, and the largest displacement of wall obtained is 41.5mm. 2. The finite element model of reinforced concrete wall was set up by adopting the explicit dynamic analysis module LS-DYNA of the large finite element software ANSYS9.0. Dynamic response of reinforced concrete wall under right-angled triangle form of explosive or impact loads were simulated, in which SOLID 164 element and material-brittle-damage were adopted. The dynamic response of the wall were obtained., and the largest displacement of wall is 51mm, which is larger than 41.5mm obtained from theoretical. The results indicate that the theory of bidirectional slab with the four sides fixation applying to analysis of the wall is accurate and reasonable and the parameters used in the 96 material model is reliable.3. Dynamic response of reinforced concrete wall with different supported condition, reinforced ratio, thickness, concrete strength, peak value and time of explosive or impact loads was obtained. The results indicate that the thickness of the wall, the reinforced ratio, concrete strength, boundary conditions have significant influence on the resisting ability of wall under explosive or impact loads. The thickness of the wall has the most important effects on the resisting ability. The displacement increases with the peak value of the pressure and the duration of the time.