Study On Design Criteria And Cutting Behavior Of Corner-type Shaped Charge Jets

So far,the ring shaped charge cutter has been deeply analyzed by many researchers,but it has not been fully applied in engineering practice.A considerable part of the reason is the lack of penetration performance analysis of several possible corner situations in the actual application of the cutter.And the influence of the different radius of curvature of the corner on the jet passing through the corner,so the design of the charge and the corner radius of curvature lacks theoretical and practical basis.Based on numerical calculations and theoretical analysis methods,starting from the principle of shaped charge effect,combined with shaped charge jet forming and penetration theories,this paper compares and analyzes the penetration performance of the coplanar shaped charge structure,as well as for non-coplanar shaped charges.The jet deviation problem of the jet is analyzed and summarized,and some basic understandings about the cutting performance of the corner shaped charge structure and the design criteria of related parameters are obtained.The research content of this paper is as follows:(1)Use ANSYS/LS-DYNA explicit finite element software to perform numerical analysis on the coplanar shaped charge structure(including convergent,straight and divergent shaped charge structures),and obtain the shaped charges respectively.The relevant data of the process of jet penetrating the metal target plate were compared to analyze the correlation of their penetrating capabilities.It was found that the penetrating performance was convergent,straight and divergent in order.(2)Simultaneously conduct a numerical analysis of the non-coplanar jet(the jet is not in the same plane as a whole),that is,the structure of the 90° rounded corner-shaped shaped charge,and compare it with the structure of the flat shaped charge.The energy-concentrating rod penetrator at the top angle of the 90° charge shaped cover,due to its asymmetry when passing through the arc corner,when the inner wall radius is satisfied r0>6z0,where z0 is the height of the shaped charge cover,the detonation wave can pass through the corner.After that,it reaches a stable state again,that is,the difference in axial cutting depth is small(less than 1%).And the normal offset of the jet is quantified,which provides a reference for the design of the subsequent 90° rounded corner shaped charge structure.(3)Analyze the force balance process in the process of jet penetrating the target through the method of establishing a physical model,and obtain the relationship between the energy consumption of the coplanar jet and the penetration depth,which mutually confirms the results of the numerical calculation.And at the same time,the numerical calculation Supplementary explanations are made on the changes in jet velocity appearing in,to show that both are in line with physical reality.(4)Simplified analysis of jet movement during the penetration of 90° rounded corner jets through theoretical analysis,and the expression of jet offset angle is obtained,combined with numerical calculations,to obtain the design criteria for the inner wall radius.Although the offset angle is still 4° under this design criterion,since adiabatic shear occurs during the jet penetration process,which consumes jet energy to a large extent,the normal offset produced by the normal component of the jet is not so large,and the longitudinal penetration depth is not different largely between before and after the corner,so this design criterion can meet the design requirements to a certain extent.At the same time,the total jet offset can be calculated from the normal velocity images of the 90° rounded corner jet and the flat jet,which can provide a reference for the subsequent non-coplanar jet corner structure design.