【作者】 曾晋春；

【导师】 王晓锋；

【作者基本信息】 南京理工大学 ， 火炮、自动武器与弹药工程， 2010， 博士

【摘要】 本文基于多体动力学、有限元、接触／碰撞动力学和数值计算等理论对某车载式火炮刚柔耦合发射动力学问题进行了探索研究,为该类武器的总体设计和结构设计提供理论依据和决策参考。使用NURBS造型理论对车载式火炮零部件进行实体建模,为接触／碰撞分析提供精确的三维几何模型；对LMS/Motion软件进行了底层开发,利用动态链接库将Lankarani和Nikravesh接触力模型嵌入到LMS/Motion软件中,通过典型构件接触／碰撞的计算与比较分析,提出了某车载式火炮主要零部件接触／碰撞问题的处理方式；以某车载式火炮方向回转轴承为对象,用VBScript编制了滚珠接触／碰撞批量建模的宏命令,建立了计及滚珠与内／外滚道、相邻滚珠间、齿弧与方向机主齿轮之间的接触／碰撞以及间隙的多刚体接触／碰撞模型,通过数值计算给出了方向回转轴承结构参数对炮口扰动和部件受力的影响规律。利用柔体-柔体接触／碰撞的模型模拟身管与摇架衬套的相互作用,通过8节点等参六面体单元和主／从节点建立身管、摇架衬套的精细有限元模型,基于Craig-Bampton模态分析理论计算主模态和约束模态,利用模态截断的方法,获得LMS/Motion柔性动力学分析所需的模态信息；以某车载式火炮为例,通过柔体间接触／碰撞模型的计算分析,得到了身管柔性、接触间隙对炮口扰动的影响规律。对土壤弹塑性变形的建模进行了探讨,使用实体单元、壳单元等单元形式对土壤、座钣和驻锄进行有限元离散,利用Drucker-Prager材料模型描述土壤的弹塑性,基于主控／从属接触搜索算法计算土壤载荷和变形之间的关系,应用最小二乘拟合法获得描述土壤弹塑性的非线性刚度曲线,对两种典型土壤的弹塑性模型进行了数值计算,给出了不同土壤对炮口扰动的影响规律。建立了综合考虑方向回转轴承接触／碰撞、柔性身管-柔性摇架衬套接触／碰撞以及土壤弹塑性的车载式火炮发射过程刚柔耦合动力学模型,通过数值计算分析,研究了土壤弹塑性、方向回转轴承、柔性身管等因素对火炮炮口扰动及关键部件受力的影响规律,数值计算结果与实测数据取得了较好的一致性。更多还原

【Abstract】 Based on multibody dynamics, finite element analysis, contact/impact theory and the correlational numerical methods, an approach toward the rigid-flexible couple launch dynamics was investigated for the trucked-mounted gun, which can provide theoretical foundation and design decision for overall design and structural design of such weapon systems.The solution accuracy of the contact problem depends upon the precision of the 3D model, so the components were modeled based on the NURBS theory. A subroutine about the Lankarani and Nikravesh contact force model was linked to extend the LMS/Motion’s contact force model using the method of dynamic link library. In light of summation on the results from dynamic responses of impact/contact between typical parts, a procedure for dealing with impact/contact problem was presented for the trucked-mounted gun. The macro edited by VBScript was used to automatically set numerous models of contact/impact between balls for the traverse bearing. By taking the contact between ball and raceway, ball and adjacent ball, gear arc and main gear of the traversing mechanism, and the clearance between ball and raceway into consideration, the dynamic model of rigid bodies system was set up for the trucked-mounted gun. The effects of structural parameters of traverse bearing on muzzle disturbance and forces acted on parts were examined by using numerical computation.The flexible-body contact method is used to construct the coupling between the barrel and cradle bush. The barrel and the bush of cradle were meshed by CHEXA element manually and the master/slave nodes technique was used. Based on the Craig-Bampton method and the mode truncation technique, the main mode and the constraint mode of the barrel and bush were used to construct the flexible bodies by LMS/Motion. Via the model of contact between the flexible bodies, the effects of the barrel’s flexibility and contact clearance on muzzle disturbance were analyzed for the trucked-mounted gun.Modeling of elastic and plastic deformation is conducted for soil. Soil, base plate, and spade were discretisized by solid and shell element, respectively. Drucker-Prager model was utilized for describing elasticity and plasticity of soil. The master/slave searching technique was used to get the relation between load and deformation. The least square fitting method was applied to attain the nonlinear stiffness curve, which was used in representing elasticity and plasticity of soil, and providing the soil model for multi-body dynamics analysis of the trucked-mounted gun. The plasticity of the two typical soil materials were numerically simulated, and their effects on muzzle disturbance were figured out.With comprehensive consideration on the multiple contacts in the traversing bearing, the contact between barrel and cradle bush, and the elasticity and plasticity of soil, a model of rigid-flexible couple launch dynamics was established for the trucked-mounted gun. The effects of the elasticity and plasticity of soil, the traversing bearing, and the flexibility of barrel on muzzle disturbance and forces acted on the key components were investigated by means of numerical method, and the simulated results were in excellent agreement with the test data.更多还原