基于无网格局部彼得洛夫－伽辽金法（MLPG）的弹带高速挤进膛线过程理论、方法及实验研究

Band engraving rifling with a high speed is a complex transient nonlinear problem under the high temperature, high pressure and confined environment, and is also in the level of experiential phenomenological theory at present. Aiming at the lack of system in-depth mechanism theory for the problem and the mesh distortion during numerical simulations using the finite element method, the transient nonlinear theoretical model for the engraving process will be established in this proposal, and the numerical simulation algorithm for the process of band engraving rifling will be investigated based on the meshless local Petrov-Galerkin (MLPG) method, and the solutions for the key issues of the effectiveness and accuracy in the numerical calculations will be investigated as well. Then, a motor driven complex mechanical and electrical experimental setup will be designed innovatively, and the dynamic engraving simulation experiments will thus be conducted, forming effective method and technology for the mechanism research of band engraving rifling with a high speed based on the accurate numerical simulations using MLPG method and the dynamic engraving simulation experiments. And then the influence rules of the geometric, structural and material parameters of the band and the rifling on the character of band engraving rifling with a high speed will be researched. The research achievements of this proposal will promote the development of transient nonlinear dynamics and supply the technical supports for the design and analysis of artillery and automatic weapon, and also will promote the applications and developments of the MLPG method in metal plastic forming field with an important theoretical significance and military and civilian application worth.

弹带高速挤进膛线问题是高温、高压、密闭环境下的复杂瞬态非线性问题，目前处于经验唯象理论层次。本项目针对该问题缺乏系统深入的机理性理论及有限元法进行数值仿真时存在的网格畸变瓶颈，建立挤进过程的瞬态非线性理论模型，研究基于无网格局部彼得洛夫-伽辽金法（MLPG）的弹带高速挤进膛线过程数值仿真算法，探索数值计算中效率和精度等关键问题的解决途径，创新设计一套由电机驱动的复杂机电实验装置，开展动态挤进模拟实验，形成一种基于MLPG法的精确数值仿真和动态挤进模拟实验结合的弹带高速挤进膛线过程机理研究的有效方法和技术手段，研究弹带与膛线的几何、结构和材料参数对弹带高速挤进膛线特征的影响规律。研究成果可促进瞬态非线性动力学理论的发展，为火炮与自动武器设计分析提供理论技术支撑，也可推动MLPG法在金属塑性成形领域的应用，具有重要的理论意义和军民应用价值。

弹带挤进膛线是高温、高压、密闭环境下的复杂瞬态非线性问题，是恶劣环境下的弹带与膛线之间高速挤压塑性成形问题，这个复杂物理过程存在着几何非线性、物理非线性、材料非线性等特征，但弹带挤进膛线过程同时是开展火炮与自动武器膛线磨损、弹带削光、检验弹带与坡膛的匹配程度、身管寿命、射击精度以及弹丸优化设计等方面研究不可缺少的基础工作。本项目针对该问题缺乏系统深入的机理性理论及有限元法进行数值仿真时存在的网格畸变瓶颈，基于刚(粘)塑性材料假设，完成了弹带高速挤进膛线过程的瞬态非线性理论模型建立，包括弹丸尾部火药气体的瞬态冲击载荷模型、弹带与膛线摩擦模型，利用分离式霍普金森压杆试验获得了弹带这种特殊合金材料的本构关系，建立了弹带高速挤进膛线过程平衡微分方程、边界条件、几何方程（变形协调条件）、本构关系、屈服准则、体积不可压缩条件，形成基本控制方程组，完成了弹丸弹带挤进过程的数值仿真分析；在无网格局部彼得洛夫-伽辽金法（MLPG）方面将多项式和径向基函数相结合，提出一种新的无网格插值移动最小二乘法，其同时具有移动最小二乘和径向基函数的特性，其中多项式系数通过移动最小二乘方法求解，径向基函数的系数通过插值函数通过影响域内的点来获取，本方法的形函数具有Kronecker delta函数特性，使得相比与传统的移动最小二乘法本质边界条件的施加更加简单；运用功能原理设计、动力学、结构优化设计、有限元等现代设计理论研发了一种由电机驱动的复杂机电实验装置，并在此装置上开展弹带高速挤进膛线过程中弹带受力、弹丸运动状态的动力学仿真分析研究，分析结果表明该装置可以有效模拟弹带的动态挤进过程。项目研究为弹带高速挤进过程的理论模型和数值仿真以及试验验证方法提供了一套完整的研究理论和方法。