| The multidimensional shaped charge structure means that a shell is assigned multiple ammunition rooms and liners evenly around its, and the explosive of every ammunition room is detonated by the same initiator. The multidimensional shaped charge is able to form multiple jets which damage the target from multiple direction after initiation. So it is the earliest applied to military field, and it is also widely used in civilian field, for example, petroleum gas perforating, the orientation fracture blasting of rock, linear shaped charge cutting and so on. In view of its widespread application value, so it has important significance for studying the multidimensional shaped charge by the numbers.Because relevant experiments involve some complicated processes which increase the difficult of experimental research, such as the detonation of the explosive, cracking of the shells and penetration of the shaped charge jet. And it can not be able to describe the complicated processes accurately and visually with traditional analytic method. Besides, the experimental cost is also the considerable factor, so another method instead of experimental study is necessary. Along with the rapid development of computer technology, the numerical simulation is a effective method. But the numerical simulation of shaped charge jet penetrating target belongs to large deformation and multi-material problems which are still the difficulties in numerical simulation field. So one of the most important research contents is to discuss and study more suitable numerical simulation methods,then design and optimize the multiple shaped charge structure and the liner,in addition, research the related theory, mechanism and penetration performance.The Smoothed Particle Hydrodynamics method(SPH) and the way of writing programs are firstly introduced, and the methods how to simulate large deformation problems using SPH and SPH-FEM coupled method in the procedure LS-DYNA are studied. Then the validity and accuracy of the two numerical algorithms are researched by comparing with Finite Element method, Arbitrary Lagrangian Eulerian method and experimental results. In addition, the influence for computational results with different initial number of neighbors per particle and different particle formulas is researched in detail. The research results show that the SPH method and SPH-FEM coupled method are adapted to simulate this kind of large deformation and multi-material problems. Based on energy principle, design and optimize different shaped charge structures and different initiation ways. Because the liner as the energy carrier is one of the most important compositions, so this paper designs and optimizes a new kind of double cone liner, and the jet parameters of the biconical liner with different structures are studied in order to acquire the optimized result through orthogonal design method, then its formation and penetration mechanism is studied by means of numerical simulations and experiments. The influence rule of the jet’s speed and explosively formed projectile’s speed under different geometric parameters of the biconical liner is researched by variance analysis method. The numerical simulation and analysis results are in agreement with experimental results.Rate of thickness change, radius of curvature and density of the liner have remarkable effects on the jet’s speed, so the numerical simulation method is used to study the influence rule. If the liner is composed of two layer materials, appropriate thickness ratio is beneficial to improve the velocity of the shaped charge jet according to the theory of transmission and reflection of shock wave. So this paper designs a king of dual-wall liner which contains copper and aluminum materials, and researches the mechanism of shaped charge jet forming by orthogonal design and variance analysis. The finally optimized copper and aluminum liner is very ideal, its tip velocity of the shaped charge jet is improved highly.Due to so many parameters difficult to measure in the present theoretical formulas used to calculate the penetration depth of the shaped charge jet into the steel target, so the theoretical formulas were combined with the numerical simulation results to achieve the purpose. Based on incompressible liquid theory, taking the nolinear of the shaped charge jet’s speed distribution into account, the dual virtual point source principle is used to calculate the penetration depth of the shaped charge jet into targets. Two computational examples and experimental research results show this way is feasible, and the established computational model has good accuracy.Based on experiments, the penetration performance of multidimensional shaped charge with different geometric structure, initiation ways and technological parameters is researched. Then the different structure and materials of powder liners produced by simple and low costly mechanical means are studied.in addition,the influence rule and penetration performance of the tungsten-copper liners with different parameters such as ratio of tungsten-copper, molding pressure, mass and so on are researched. Take two engineering blasting projects(the drill-jamming accidents and blasting of rocks under the pier) for example, the special blasting technology solutions under complex environment are made taking advantage of shaped charge efficiency. A kind of multi-directional linear cumulative cutter and single directional shaped charge cutter is designed respectively according to the real situation of the two projects. The mechanism, effect of cutting and security of the two designed cutters are researched by numerical simulation and experimental methods. The are ideal results when the two kinds of cutters are applied to engineering practice, which provide important reference for similar projects. |
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