【作者】 梁超；

【导师】 胡德安；

【作者基本信息】 湖南大学 ， 机械工程， 2013， 硕士

【摘要】 子弹侵彻混凝土靶板问题一直是武器研制和工程防护部门关注的重点，对侵彻过程和侵彻机理的研究在战斗部设计、毁伤效应评估等方面有重要意义。针对混凝土侵彻响应问题，以往开展了大量的实验和数值模拟研究。实验方法往往只专注于弹靶在终点时刻的状态。而数值模拟则可以借助于计算机求解侵彻过程连续介质物理方程组，它不仅可以在一定程度上再现子弹在靶体中侵彻的弹道轨迹曲线，还能得到各物理量的时间历程，从而有助于对侵彻过程进行进一步分析。混凝土靶侵彻数值模拟研究通常采用侵蚀有限元方法(FEM)，该方法具有计算效率高的优势，但将畸变单元从模型中删除容易造成计算模型总能量损失，使得计算结果的精度得不到保证。光滑粒子流体动力学(SPH)法能有效地避免网格畸变，并能自然地模拟材料的破坏、飞溅等现象，但相对较低的计算效率也成为其应用于三维建模分析的瓶颈。FEM与SPH方法在模拟高速冲击问题时各有优缺点，为了集两者优势于一体，近年来国内外开始对SPH与FEM的耦合方法进行研究，并取得了一些成果。本文就是在该背景下，基于Johnson和肖毅华等关于耦合算法的研究工作，结合具体的素混凝土及钢筋混凝土的侵彻实验，将三维FE-SPH自适应耦合计算方法应用于计算研究混凝土侵彻问题。本文首先综述了混凝土侵彻问题和FE-SPH自适应耦合算法的国内外研究现状；然后简要介绍了SPH算法以及FE-SPH自适应耦合算法；随后采用FE-SPH自适应耦合算法对几种具体的混凝土侵彻问题进行了研究。在对混凝土侵彻问题进行研究时，首先探讨了素凝土靶板的正侵彻问题，该问题主要专注于侵彻过程量的研究，并与实验进行了对比分析。其次研究了子弹斜侵彻素混凝土靶板的跳飞问题，在进行跳飞问题研究时，得到了不同厚度靶板的临界跳飞曲线。最后研究了子弹侵彻钢筋混凝土问题，在该研究中通过多次数值实验，着重研究了体积配筋率和子弹着靶点对侵彻的影响。本文的研究成果对于战斗部的研制和结构的防护设计都有一定的指导意义和工程应用价值。更多还原

【Abstract】 The researches of projectile penetrating concrete have great significance toweapons development and engineering protection department. And study of thepenetration process and law of penetration has great implications to the weaponwarhead designs and the effect evaluation of damage. Previous researches onexperiment of concrete target have paid more attention to the projectile and target inthe final conditions. With the help of computer to solve continuum physics equationsof the penetration process, numerical simulation can not only reproduce the trajectorycurve of the projectile in the target, but also can get the time history of each physicalquantity, which is great help to make further study to the process of penetration.Penetration of concrete plate subjected to high velocity impact is often simulatedby finite element method (FEM), which has high computational efficiency. But highvelocity impact problems often involve severe deformation of materials, which maylead to extreme element distortions. Removing distortion elements through erosiontechnique from the model is most likely to cause total energy loss, and accuracy ofcalculation cannot be guaranteed at the same time. Smoothed particle hydrodynamics(SPH) method has an advantage in treating large deformations, and it can naturallysimulate damage and splash phenomenon of materials. But its relatively lowcomputational efficiency limits its application in three-dimensional (3D) modelingand analysis. Therefore, in order to take advantage of both FEM and SPH method, lotsof effort had been dedicated to the coupling of SPH and FEM in the past years.In this background, based on the experiment of projectile penetrating pain andreinforced concrete target, several numerical models are established by3D FE-SPHadaptive coupling algorithm, which is based on the works of Johnson and Xiao et al.At the beginning of this paper, recent developments of concrete penetration problemand the adaptive FE-SPH coupling method at home and abroad are briefly summarized.Then, the SPH algorithm and the FE-SPH algorithm of adaptive coupling areintroduced. After that, the FE-SPH adaptive coupling algorithm is used to studyseveral concrete penetration problems. In the study of the concrete penetrationproblem, the projectile normal penetrating into plain concrete target is firstlydiscussed, this study mainly focuses on penetration process, and the results ofsimulation are compared to the experimental results for further analysis purpose. Secondly, the phenomenon of ricochet of projectile penetrating into plain concrete issimulated, and the critical ricochet curve of different thickness target is acquired.Thirdly, the projectile penetrating into reinforced concrete is studied, and studiesmainly focuses on the influence of reinforcement ratio and impact position to thepenetration.The results of this paper have a certain guiding significance and engineeringapplication value to the protection design and structure of warhead.更多还原