Plastic Dynamic Response Of The Reinforced Concrete Plate Subjected To Explosion Load

Due to the structure is subjected to explosion load of short time and large amplitude, it becomes complex and heavy to analysis its whole action progress under blast. To study the dynamic response of a plate widely used as antiknock component under explosion is of practical engineering significance for structural antiknock research. In this paper, two measures consisting of the theoretical analysis and numerical simulation are employed to investigate the plastic response of reinforced concrete rectangular plate subjected to blast,which contributes to the contents as follows:1. By idealizing concrete as perfect rigid-plastic material, the plastic hinge lines of rigid-plastic rectangular plate at limit state are formed based on energy method and plastic theory. There are two different kinds of plastic failure mechanics coming into being by plastic hinge lines, while the balance equation of small deformation condition listed respectively.2. Usually large deformation of plate comes up when under explosive load, which would be restricted by boundary supports. The effect can be called as surface force effect by simplifying it into force reaction on the middle surface. To consider middle surface force effect in, the membrane force factor is defined by calculating the energy absorbing power of plastic hinge lines according to the principle of maximum dissipated energy.3. The balance equation of large deformation is obtained by adding membrane force factor into that of small deformation. The corresponding balance equations of the two different kinds of plastic failure mechanics with small and large deformation are established for the plate under simplified triangular explosion load. And the whole dynamic responses of the rigid-plastic rectangular plate under medium and high explosive loads are obtained.4. The numerical simulation to research the dynamic response of the reinforced concrete rectangular plate under blast is carried out by explicit dynamic finite element software ANSYS/LS-DYNA with reasonable method. The results show that if the elastic or plastic deformation of the plate comes about is depended on the explosive charge; and the plastic deformation is more available with the lower steel ratio; the concrete strength has little thing to do with the failure modes of plate; and the more boundary constraints, the higher stiffness of plate is enhanced by surface force effect.5. Meanwhile, the numerical results show two different failure modes of the reinforced concrete rectangular plate under explosion, which is similar with the results of theoretical analysis in this paper. That proves the theoretical analysis is considerably available to analyze the deformation and failure modes of the reinforced concrete plate under blast.