冲击载荷作用下的筒型摇架虚拟设计

【作者】 陈显呈；

【导师】 杨国来；

【作者基本信息】 南京理工大学 ， 机械工程， 2012， 硕士

【摘要】 本文以某总装预研课题和国防“973”项目为研究背景,利用有限元动力学、实验测试、优化设计以及科学可视化技术对火炮冲击载荷作用下筒型摇架的虚拟设计问题进行探讨研究。探讨了复杂结构高精度有限元网格建模技术,采用了“蒙皮法”过渡实体和板壳单元,保证了建模精度,提高了建模效率。研究了筒型摇架承受的瞬态冲击载荷模型、平衡机的等效模型以及约束关系。同时为了保证建模的通用性和一致性,开发了通用的参数化建模模块。基于静态刚强度准则,分析了不同工况下筒型摇架的刚强度情况。在考虑平衡机非线性的基础上建立了摇架动态刚强度模型,利用数值计算的方法获得了动态冲击载荷作用下筒型摇架各部位的动态应力及位移响应规律。构建了摇架动态应变的测试系统,对摇架关键部位的动态响应进行了测试,并与有限元计算结果进行了对比分析,验证了筒型摇架刚强度虚拟设计分析的可行性。以摇架轻量化为目标,采用了混合参数化建模技术,建立了数学优化模型和优化环境。根据多岛遗传算法,在满足刚强度要求下,对筒型摇架实施了局部优化研究。基于OpenGL接口,开发设计了有限元数据场重构软件。在软件环境下对三维数据场进行网格模型、消隐模型和云图重构显示,讨论了不同云图绘制算法对显示结果的影响,为虚拟设计系统可视化开发提供借鉴。本文取得的摇架刚强度虚拟设计初步研究成果对该类机构的数字化设计具有一定的参考作用。更多还原

【Abstract】 Under the background of an Advance Research Project from the General Armament Department and a National Defense 973 Project, this paper is concerned with virtual design of cradle on the impact load during the firing of cannon by finite element dynamic method, experiment test, optimal design and visualization in scientific computing.Grid modeling method of finite elements with high precision for complicated structure is discussed. Skinning method is used for transition between solid and shell elements, which ensures the precision of modeling and enhances the efficiency of modeling. Transient impact load model acted on the cradle, equivalent model of equilibrator and constraint relation are investigated. To ensure the consistency and versatility of modeling, a general module for parametric modeling is developed.Based on the static stiffness and strength criterion, the stiffness and strength of cradle is analyzed in different conditions. The dynamic model of cradle is built, in which the nonlinearity of equilibrator is taken into consideration. By the method of numerical calculation, the dynamic stress and displacement of cradle subjected to impact load is obtained. A test bed for measuring dynamic strain of cradle is constructed, and the dynamic response of several key positions is tested. Tested result is analyzed and compared with that computed by FEM, which verifies the feasibility of virtual design.Aimed for lightweight of cradle, hybrid parametric modeling technology is investigated, and the mathematical optimization model and optimal environment are developed. In light of constraint condition of cradle stiffness and strength, cradle is partly optimized by multi-island genetic algorithm.Based on the OpenGL interface, reconstruction software for FEM data is developed. Grid model, hidden model and nephogram model are reconstructed from 3D data field under the software environment. The influence on nephogram display generated by different algorithms is discussed, which can be referable for visualization development of virtual design system.The preliminary findings of virtual design for the stiffness and strength of cradle achieved in this paper can be of certain reference to digital design of such mechanisms.更多还原