The Study On The Influencing Factors Of Penetration Depth Of Expanded AN Explosive Linear Charge

In modern society,Explosive jet technology is widely used not only in military field,but also in aerospace,petroleum exploration,geotechnical exploitation ship disintegration,steel structure cutting and many other aspects.There are many studies on the formation mechanism and penetration depth of shaped charge jet under the action of high-energy explosive,but few studies on linear shaped charge cutting with expanded ammonium nitrate as the main charge of civil explosive.However its application prospects are broad.Therefore,it is significance to study the factors affecting the depth of shaped cutting and the penetration of shaped steel.Firstly,the formation and penetration of linear shaped metal jet are studied.Constant and Quasi-steady incompressible fluid mechanics theory are elaborated.The influence of cone angle and thickness of liner on metal jet was calculated and analyzed.The better range of technological parameters of shaped charge was determined preliminarily,which provided guidance for the determination of experimental scheme.The related characteristic parameters of jet are calculated on the basis of Gnrnay semi-empirical formula.Secondly,the experiment of shaped charge cutting with expanded ammonium nitrate explosive as main charge was designed and implemented,and the optimum technological parameters were obtained from the analysis of results.The maximum penetration depth can be obtained when the charge height is 30 mm,the liner thickness is 1.0 mm,the explosion height is 50 mm and the cone angle of the liner is 80°.Comparing the calculated jet velocity with the numerical simulation results,it is found that the error between them is small;comparing the penetration depth of the experimental results with the numerical simulation results,it is also found that the error between them is small.Finally,the numerical results of AN explosive forms shaped jet penetrating steel target are calculated by using Ansys-Lsdyna dynamic finite element software.Accordingto the results of numerical simulation,the formation of jet cutter and the process of penetrating Q235 steel target are described.Comparing the calculated results with the experimental results,it is found that the error of penetration depth between the two methods is under 16%.The error shows that ALE fluid-structure coupling algorithm is suitable for simulating the formation and penetration of jet.The results of simulation and experiment are analyzed and compared.When expanded ammonium nitrate explosive is used as the main charge and the charge height is 30 mm,the thickness of liner should be1.0 mm,the cone angle of liner should be 80°,and the explosion height should be 40 mm.So the maximum penetration depth of copper jet knife into steel plate is 25 mm.At the same time,the penetration simulation of section steel is studied.It is found that the metal thickness L in the cutting direction affects the penetration ability of jet cutter into I-beam.It is pointed out that the optimum cutting angle ranges from 45 degrees to 55 degrees.The calculation results show that the I-beam of the specification in this paper can be perfectly cut at this cutting angle.