Dynamic Response of the Concrete Column under Explosive and Impact Loads
|Keywords||explosive impact load reinforced concrete columns dynamic response FEM|
In the current era of peace and development, terrorism is spreading and the terrorist bombing activities on the international community peace and tranquility of a great threat. Whether in defense or in the industrial structure, the structure of buildings, usually need to consider the role of the explosive and impact loads. Study of the dynamic response of a project in the area under explosive and impact loads are very concerned about the issue. It is different from response analysis under earthquake because of the locality and brevity of the blast load. Since the study on a single component of the explosive response lays a good foundation for studying the overall structure of dynamic response under intense dynamic loading, thus the research on component of the dynamic response under the blast load is very important theoretical significance and value of projects.The energy conservation principle and the structural dynamics theory are applied to study and analyze a simplified model of a frame column to obtain the deflection curve of this simplified column, middle theoretical static displacement, vibrational frequency of structural system and the maximum middle dynamic displacement under uniform distribution explosion loads. Through simplifying, their simplified formulas under the special end constraint condition, such as simply supported at an end and fixed at other one and fixed at both ends are concluded respectively.In this paper, large-scale of finite element analysis software LS-DYNA is used to simulate numerically the dynamic response of columns based on different constraints under explosive and impact loads. By means of the maximum middle displacement and the corresponding relation between the displacement and the ratio of duration of loading to the structural natural vibration period, the author obtains dynamic factor of five groups columns based special end constraint condition under explosive and impact loads and draws displacement response spectrum curve. By using the LS-DYNA to simulate the dynamic response of a reinforced concrete square cylinder fixed at both ends under explosive and impact loads, the displacement and the failure are respectively discussed under different scaled distance in order to analysis qualitatively on the antiknock performance. In this paper, the theoretical analysis and numerical simulation were carried out on the dynamic response of reinforced concrete columns under explosive and impact loads. Some conclusions and results received from this paper provide a basis for the analysis on the structure under explosive and impact loads.