复杂零件结构设计的概念单元方法

A Novel Approach for Conceptual Structural Design of Complex Machine Elements

提出复杂零件结构设计的概念单元方法,即几何与物理模型、概念构型与单元、强度与刚度、工艺与造型四部分。分析了复杂零件的应用场合和结构特点,建立几何实体与物理模型,包含联接与安装部位,设置工况载荷与约束,定义设计区域与非设计区域;采用结构拓扑优化方法获得在若干工况下零件实体内部的传力路线,综合多工况下传力路线和相关因素,构造出复杂零件结构的概念模型,并结合零件的载荷形式,综合考虑制造工艺性,选择合适的零件结构单元;依据零件的强度或刚度要求,使零件壁板和结构单元具有满足性能要求的尺度;同时,兼顾零件结构工艺性和视觉美学效果等因素,对零件结构形状和尺度进行工艺和造型再设计;以加工中心立柱和三级齿轮减速器箱体为例展示了结构设计过程,通过合理布置零件内部筋板、单元的结构形式和尺寸,为复杂零件的轻量化和科学合理结构设计提供有效方法。

A novel approach of Conceptual structural design of complex machine elements is presented. The approach consists of the four parts： building a geometric-physical model, setting up the conceptual model and construction units, calculating of the strength and stiffness, and designing of the structural manufacturability and aesthetics. By analyzing structural characteristic of complex machine elements, a geometric model, a simple geometric shape, are designated, which includes all connection and assemble surfaces. And the physical model implies a finite element model with loads and connection constraints incorporated. The conceptual model is to form a skeleton of the machine part by means of the material optimal distributions, or structural topological optimization, in different load cases. Meanwhile, the structural units are discussed respectively, which corresponds to the different cases of the load and manufacturability. Based on the structural skeleton with structural units, the dimensions of the machine parts are determined by the required structural strength and stiffness. Finally, by taking into account the manufacturability and aesthetic appearance, a conceptual structure with the required dimensions is accepted as the actual structure of the machine part. Both a machine center pillar and a gearbox are taken as examples to illustrate the design process, which demonstrates that the proposed approach is not only high efficient for the reasonable structure design, but also an effective way to light-weight structure design for complex machine elements.