Research Of Detonation Propagation Characteristics On Superposition Explosive Materials

In the smooth blasting, presplitting blasting, stone-material exploitation blasting and mid-deep-hole blasting, the charge structure of detonating cord in a lengthways superposition charge is often used. Though the detonation propagation characteristic of superposition explosive materials has been primarily studied and made some conclusion in this field, which is still not be approbated due to the complicacy of detonation and the limitation of experiment condition, the propagation state of detonation wave of superposition explosive materials with different detonation velocity and the intrinsic relation of propagation process via detonation velocity of the materials should be studied on the basis of experimentation and theory. In this dissertation, the propagation state of detonation wave of superposition explosive materials, based on many groups of experiment data, is systematically studied with the methods of theoretical analysis and numerical simulation. The main original works include:Utilizing the classical theory of C-J and Z-N-D, three detonation reactive mechanisms of condensed explosive, i.e. the whole reactive theory, the surface reactive theory or hotspot theory and the mixed reactive theory, are introduced and, the adaptive condition of this mechanisms are pointed out, respectively. Further more, the basic notion about superposition explosive materials is definitely expatiated and, the detonation propagation process of superposition explosive materials is explained by using the above mechanisms.The experimental data indicate that whether the initial detonation velocity is high or low, the detonation wave propagates along the superposition section in the maximum velocity among the detonation materials after explode for each other and, the whole detonation process can finish in a short time. As the influence of the detonation velocity, the other parameters of detonation wave surface are also changed obviously. Therefore, when the low detonation velocity explosive material is superposed to a high detonation velocity explosive materials in a lengthways, the detonation propagation time can be shorten and the efficiency of explosive energy be improved remarkably.The process of detonation propagation of superposition explosive material is displayed objectively in different conditions by using the method of numerical simulation. The numerical result is consistent with the results of the experiment and theoretical analysis. So the rationality of theoretical analysis has been validated. On the other hand, it is shown that LS-DYNA 2D software could be used to simulate the process of detonation propagation of superposition explosive materials.By using the methods of the theoretical analysis, experiment and numerical simulation, the propagation state of detonation wave of superposition explosive materials is systematically studied and, some conclusions are obtained which can provide some technical supports for the study and practice engineering. Furthermore, the existing formula for detonating cord velocity in antitheses is amended on the basis of this conclusion, which makes the computational result more reasonable and accurate.