Research On Energy Distribution Of Explosive In Rock Fragmentation

At present, explosive energy is widely used in almost all industrial fields. The research on energy distribution of explosive in medium over the past few decades have been uninterrupted, but the investigation related to the problems of explosion dynamics is a very difficult in theoretical and experimental task.It is known to all that two basic forms of energy release in the process of explosive detonation. The first type of energy is called shock energy. And then the second type is called gas energy. Seldom researches have been done on the testing of blasting strain wave of the cylindric and concentric charge in rock, because of the complexity of blasting mechanism. So, we carried out the testing of energy parameters of blasting.Firstly, the parameters of the shock wave energy and gas bubble energy were obtained by experimental test on cylindric and concentric charge of underwater explosion.Compared with the peak value of shock wave pressure and specific shock wave energy and specific gas bubble energy.It can draw a conclusion that the cylindric charge is superior to concentric charge.Secondly, a set of practical and reliable super-dynamic strain of the test system was established by research on the super-dynamic strain. It is helpful to get the stable reliable explosion signal.Thirdly, it is tested that the blasting strain wave in the cylindric and concentric charge in different measuring point by use of super-dynamic strain test system. It can find that the two charge have great differences in details by identified and analyzed the two strain wave.Fourthly, the relationship between stress wave energy and proportional distance in cement mortar model is calculated from the waveform of parameters in various measuring point, and the rule of strain wave propagation in rock can obtain by variations of strain peak. The strain wave amplitude decays with the distance between the medium particle and the blasting centre increasing, and also the strain wave changes.Fifthly, a numerical simulation for the blast loading in cement mortar model was carried out in the paper. In order to simulate the nonlinear dynaimc process in cement mortar model, the ALE fluid-solid coupling algorithm is available in ANSYS /LS-DYNA.The JWL (Jones-Wilkins-Lee) equation of state is used to model the pressure versus volume relationship. The law of propagation of stress wave was vividly demonstrated based on numerical analysis of propagation of stress wave. The concentric charge in the rock spreads with spherical explosions, but the cylindric charge shows on hemispherical in both ends and cylindrical approximation in lateral sides. Numerical simulation results basically reflected blasting dynaimc process of cylindric and concentric charge in rock.