变壁厚球缺型EFP战斗部结构优化设计

为研究聚能装药结构参数对爆炸成型弹丸性能的影响,利用LS-DYNA软件对EFP的成型过程进行三维数值模拟,用正交优化法分析药型罩壁厚、曲率半径、罩口罩顶壁厚比、壳体厚度对EFP成型的影响规律。结果表明:药型罩壁厚是影响EFP速度的主要因素;并得知口径为40mm变壁厚球缺型EFP,当药型罩顶壁厚为2.1mm、曲率半径为30mm、罩口罩顶壁厚比为0.4、壳体厚度为2mm时,EFP具有高的初速、流线外形、高密实度、大长径比。     

球缺形药型罩形成EFP的数值模拟及其优化设计

利用ANSYS/LS-DYNA软件对球缺形药型罩形成EFP的过程进行数值模拟,着重分析药型罩厚度和装药的长径比L/D对EFP成型的影响.通过观察EFP成型过程图和分析EFP节点的速度曲线图,得到EFP的成型过程与理论分析相符合.在药型罩厚度增加时EFP的速度不断减小、头部越来越钝,随着装药的长径比L/D增大,EFP的速度也在增大,达到L/D=1.75后速度增长减慢.在装药半径为6.5cm的EFP战斗部中的最优设计参数为：药型罩厚度为0.4cm,装药的长径比L/D为1.5.     

双面槽药型罩参数对MEFP成型影响的数值模拟

在整体式药型罩内外面预制沟槽将药型罩划分为三部分,设计一种新型MEFP战斗部。应用LS-DYNA软件对其成型过程进行数值模拟,研究刻槽参数对成型的影响,得到刻槽深度及药型罩曲率半径比与子EFP长径比的关系曲线。结果表明,刻槽深度与曲率半径比对MEFP的成型有较明显的影响。刻槽深度在1/7H～1/5H之间、曲率半径比在1.25～1.5之间时,双面刻槽药型罩MEFP形成的子EFP长径比在3～5之间,成型较为理想。     

EFP飞行速度衰减计算及仿真研究

为研究EFP飞行速度衰减规律,采用了数值模拟和理论计算相结合的方法对15组不同结构药型罩所形成EFP的速度衰减规律进行了研究.研究发现存在最优药型罩结构使EFP速度衰减率最低.理论公式计算得到的速度衰减率和数值模拟仿真结果相吻合,可以为EFP设计提供参考依据.     

隔板结构参数对EFP成型的影响

为研究隔板在聚能装药结构中的应用问题,采用LS-DYNA仿真软件,以装药口径80 mm、药型罩曲率半径和厚度分别为80 mm和5 mm的聚能装药结构为例,针对隔板的结构参数(隔板直径d,隔板圆柱高度s和罩顶药高h)对EFP成型的影响进行了数值模拟研究,并且利用正交优化的设计方法计算了各因素对EFP速度和长径比的影响因子.通过数值模拟得出了不同因素对EFP成型过程中速度和长径比的影响,获得了EFP成型较好的隔板结构参数,其中隔板直径d为48 mm,隔板圆柱部高度s和罩顶药高h分别为15 mm和24 mm.正交优化结果表明,各因素对EFP头部速度影响的主次顺序为h,s,d,对长径比影响的主次顺序为d,h,s.     

双锥形线性EFP设计与仿真研究

基于双锥形药型罩的优点,采用线性EFP设计思想,提出了一种双锥结构的LEFP的设计方法.将线性EFP的药型罩设计成双锥形结构,应用ANSYS/LS-DYNA软件对其进行数值模拟仿真,分析了不同双锥位置时线性EFP的初速及侵彻钢靶效果.结果表明:合适的双锥结构较常规锥形罩可以明显提高该种战斗部的毁伤效果,从而为提高LEFP的防空反导能力提供参考依据.     

某椭圆形药型罩的设计与数值模拟研究

本文提出了某种椭圆形药型罩的设计方法,并对部分模型进行了数值模拟计算,计算结果显示,椭圆药型罩继承了正圆曲线药型罩的优点,并且具有其他种类药型罩不具备的特点,使之成为EFP、JPC、SSJ类装药结构较好的选择对象.     

中心孔对刻槽式MEFP成型及毁伤影响的数值模拟

刻槽式MEFP战斗部在爆轰压强作用下,可形成多个具有一定质量和速度的子EFP。应用ANSYS/LS-DYNA软件,对刻槽式M EFP战斗部成型及毁伤钢靶过程进行模拟,主要研究中心孔的大小对刻槽式MEFP成型及毁伤的影响。结果表明:中心孔相对直径小于0.0323时,子EFP速度及发散角随中心孔直径增大而显著增大;中心孔相对直径大于0.0323时,子EFP速度及发散角随中心孔直径增大变化不明显;中心孔变大,子EFP长径比增大;中心孔相对直径为0.0323时,战斗部毁伤效果最好。     

曲率半径和壁厚对EFP成形性能的影响

就等壁厚球缺药形罩的曲率半径、壁厚对EFP成形性能的影响进行研究,利用有限元分析软件对曲率半径、壁厚对EFP成形的影响进行一系列数值模拟,根据模拟结果描绘出曲率半径和壁厚对EFP速度和长径比的影响程度曲线,为进行EFP优化设计提供了参考依据.     

多功能战斗部毁伤元动态形成特性数值模拟与试验研究

某型单兵火箭弹采用爆炸成型弹丸（EFP）和预制破片复合多功能战斗部,为了研究EFP和破片毁伤元动态飞散特性,笔者使用非线性动力学分析软件AUTODYN对战斗部动爆过程进行仿真计算,结合弹道空炸动爆试验,使用高速摄影对EFP和破片动态飞散特性进行记录分析,结果表明AUTODYN仿真计算结果与试验结果吻合度较好,可为后续设计提供参考。     

EFP Warhead Missile Fuze Analysis and Simulation

The explosive formed penetrator (EFP) warhead missile projects the blast fragments in one direction normal to the missile longitudinal axis. Through analyzing on the two restrictions of EFP warhead explosion: trajectory restriction and attitude requirement, the concept of fuze time-delay tolerance is presented to be the measurement of the time of the EFP warhead explosion. The calculation models of fuze time-delay tolerance under two restrictions are provided. Some crucial parameters playing important roles in calculation under attitude requirements are simulated. The simulation results show that the engagement plane angle, roll rate and warhead attack standoff influence the tolerance dramatically.     

Optimized design of biconical liner by orthogonal method

A biconical liner was optimized to improve its penetration ability. Its formation and penetration mechanism was studied through numerical simulation and experiments. And the influence of different liner geometry sizes on the jet performance was analyzed using the orthogonal method. The liner formed the high-speed jet with an explosively formed projectile. The small angle 2α remarkably influenced the jet speed which was inversely proportional to 2α. And the liner thickness t' and large angle 2β had highly significant effect on the projectile speed. The liner was optimized at t' = 0. 14 cm,2α = 50°,2β = 135°,N = 0. 4 or 0. 5,when its jet speed respectively is at 6 613 m /s and 6 839 m /s and projectile speed is at 2 247 m /s and 2 095 m /s,steel target penetration is at 8. 24 cm and 8. 31 cm,and aperture is in 2. 12 cm and 2. 08 cm. The results show that target is penetrated by the high-speed jet and high-speed projectile resulting into double damages. The penetration ability is improved greatly.     

侧向载荷下圆柱壳体断裂的ALE法数值模拟

为了了解侧向爆炸冲击载荷下圆柱壳体断裂过程,采用任意拉格郎日-欧拉方法、爆轰产物采用JWL状态方程对侧向爆炸冲击载荷作用下圆柱壳体断裂过程进行了数值模拟和分析．模拟结果表明,圆柱壳体爆炸断裂所需炸药量与壳体壁厚为递增线性关系,且这个线性关系的斜率随壁厚不同而改变．在其他条件相同的情况下,壳壁越厚,增加炸药量爆炸时壳体单元最大应力增加越慢．     

寒区隧道温度场及保温隔热层研究

为评价隧道保温隔热层效果，利用三维瞬态有限元程序，分析了隧道保温隔热材料厚度为0.0、3.0cm情况下二次衬砌及周边围岩的温度变化过程；研究了温度应力分布及其可能导致的混凝土开裂，对保温隔热材料的防冻效果进行了评价。计算表明：设3.0cm厚的保温隔热材料层后衬砌温差小，能较好地保护二次衬砌免受温度应力影响，避免了二次衬砌产生开裂等冻害，分析结果具有一定的工程参考价值。     

衬层弹性变形对水润滑结构润滑性能的影响分析

以水润滑轴承为例,利用有限元耦合算法数值计算了水润滑结构的弹流润滑模型,从理论上分析了具有不同弹性模量值和厚度值的橡胶衬层弹性变形对水润滑结构水膜压力、水膜厚度和摩擦磨损特性的影响规律。研究表明:衬层弹性变形对水润滑结构的弹流润滑性能有着非常大的影响,其影响效果在弹性模量值和厚度值较大时更为明显;相同的工况下,随着衬层弹性模量值的减小,水润滑结构的轴向和周向水膜厚度皆升高,水膜压力降低,压力作用区域扩大,弹流润滑效果更好,从而减轻了结构的摩擦磨损;一定程度上,衬层弹性模量的降低和衬层厚度的增加在增强水润滑结构的弹流润滑效果上是等效的。     

The properties of the sintered copper powder liner

In order to study the properties of sintered copper powder shaped charge liner, the copper powder, whose particle size was below 20 μm, was chosen as the main material. The mixed powders were directly pressed into the desired shape of the shaped charge liner by the top direct-pressure way. The microscopic morphology of the spinning shaped charge liner, the sintered and non-sintered powder liners, and the particle properties of the copper powder were studied with scanning electron microscopy. The experimental results showed that the irregular copper powder could get together effectively and sintering could improve the compactness of the powder liner effectively. The wall thickness and density of the non-sintered and sintered liner were also tested, and it shows that sintering causes the wall thickness thinned and the density improved. The penetration depths of non-sintered powder liner, sintered powder liner and the spinning copper plate liner were tested with different standoff respectively, showing that the penetration properties of sintered powder liner are well.     

Deformation Analysis and Stability Evaluation of the Main Shaft at Jinchuan Mine No.3

Unexpected,serious deformation failures have occurred during construction of a main shaft. A study of con-struction parameters of the main shaft is required. First,the stability of the shaft and wall-rock is investigated by nu-merical methods. The modeling results are as follows: The convergence of shaft liner is greater than 60 mm at a depth of 650 m; the maximum principal stress in the liner approaches 190 MPa,which exceeds the strength of the liner,so it is inevitable that the liner deform locally. Second,stability analysis of shafts with different liner thicknesses has been completed. The results have the following features: If the depth where the liner thickness is increases from 400 mm to 500 mm is 650 meters,the convergence deformation of the liner is reduced by 3.4 mm while the maximum principal stress is reduced by 5 MPa. At a depth of 250 m if the liner thickness is increased from 400 mm to 500 mm the conver-gence of the liner is reduced by 1.5 mm while the maximum principal stress is reduced by 10 MPa. Therefore,increasing the liner thickness has little effect on liner convergence but can reduce the maximum principal stress in the liner. The thickness of the liner can be increased to reduce the maximum principal stress and increase the capacity for shear defor-mation. Finally,construction techniques employing releasing-displacements have been numerically simulated. The con-clusions are that as the releasing displacement is increased the convergence of the surrounding rock increases linearly while the convergence of the lining decreases linearly. The plastic zone in the surrounding rock mass at first increases linearly but then,at a release-displacement of 95 mm,expands rapidly. These conclusions show that use of suitable re-leasing displacement can increase the self-supporting capacity of the surrounding rock. But when the releasing dis-placement exceeds 95 mm the plastic zone rapidly enlarges and stability rapidly decreases. The maximum principal stress of the lining also decreases as the release-displacement increases. There is a definite inflection point in the rela-tionships involving releasing displacement. When the releasing displacement passes this point the effect on principal stress decreases. In conclusion,a reasonable releasing displacement value when lining the shaft is 95 mm.     

双层壳结构抗冲击性能仿真研究

对潜艇结构冲击响应(加速度)的分析可以评价结构的抗冲击能力并为提高结构抗冲击性能提供依据.以某潜艇的结构和型线为基础,利用大型有限元计算软件ANSYS/LS DYNA计算了双层壳结构在改变外层壳体(简称外壳)及内层壳体(简称内壳)的厚度时的冲击环境,分析了双层壳结构在不同工况下的冲击响应,讨论了外壳和内壳对双层壳结构冲击环境的影响.通过数据分析表明:在改变外壳及内壳板厚的情况下,外壳及内壳的冲击响应(加速度)近似服从威布尔分布,内部结构的冲击响应近似服从正态分布;在同一冲击因子下,改变外壳板厚和内壳板厚对结构各部分的冲击响应影响不同.这对于潜艇的抗爆炸抗冲击分析及合理的结构形式具有重要意义.     

填埋场成层衬垫污染物运移参数等效模型

为了高效评价填埋场成层衬垫的防污性能，提出基于时间矩卷积的污染物运移参数等效分析模型. 给出多层衬垫等效渗流速度和扩散系数表达式；采用土柱实验数据验证模型的合理性和可靠性；基于衬垫系统底部相对浓度、瞬时通量及累计通量等对填埋场土工膜（GM）+压实黏土衬垫（CCL）+天然衰减层（AL）及GM+钠基膨润土防水毯（GCL）+AL不同复合衬垫进行等效计算. 结果表明，衬垫底部相对浓度更适合等效计算. 随设计水头与AL厚度增加，GCL复合衬垫的防污性能较好. 基于Cl^?击穿时间100 a标准，当水头为15 m时，与采用CCL相比，采用GCL复合衬垫可以使总厚度减少0.45 m. 土工膜防污能力随水头增加而增强，土工膜等效的CCL厚度随服役年限呈对数线性增大.