机械结构对称破缺的概念体系及设计知识研究

发布时间：2018-11-27 07:01

【摘要】：结构对称破缺是产品结构演化过程中一个普遍而有趣的现象。在原创设计中,结构对称、对称破缺的应用规律和应用方法可为设计人员科学的、有区别的、有目的的应用结构对称破缺实现产品功能、提高产品性能、满足设计约束提供系统性的指导。在改进设计及优化设计中,对称和对称破缺结构的不同功效及机械产品结构对称性程度的改变所带来的功效上的变化规律,可指导设计人员通过改变结构的对称性程度来实现产品设计需求。作为机械对称性理论的重要组成部分,本文的研究将为建立完善的机械对称性理论做出重要贡献。在深入分析当前各领域对称破缺的存在和研究现状基础上,从以下方面展开对机械对称破缺理论的阐述:1、建立完善的机械结构对称破缺的概念分类体系。全面系统地搜集有关对称破缺的机械结构实例,整理分类并建立实例库,研究实例的对称主体、对称组元、对称基准和对称操作四大对称性要素的破缺形式和破缺程度,在此基础上建立一套比较完善的机械结构对称破缺概念体系。2、建立机械结构对称破缺的破缺度评判模型。设计一套评定算法,计算机械结构对称破缺的破缺程度,用以区分机械机构对称和对称破缺。建立的评定算法以单因素方差分析为基础,对对称性要素的破缺量进行数学计算,从而得出结构的破缺程度,计算结果越大,表明结构的破缺程度越大,其对称度越低。3、总结对称破缺应用于机械产品设计中的设计知识。基于大量实例的分析,系统的研究机械对称性结构在对称度变化时其功能、性能的演变方式,挖掘出具有一定普适性和实用性的设计知识,进一步拓展对称破缺知识的应用范围。4、研究机械结构对称破缺的应用方法。通过列举实例,把在机械设计中对称破缺的设计知识的应用原理、应用方法进行比较研究,明确各自的应用规律及应用范围的异同,给出若干机械结构对称性在实现常见设计需求中的应用方法,对结构对称破缺的实际应用提供指导。本文的研究集中于机械结构对称破缺,系统的研究了结构对称破缺在机械系统中的存在形式,破缺程度的判别方法,总结了对称性结构对称度变化与功能、性能演变关系的设计知识,建立了机械结构对称破缺的若干应用方法。本文的研究成果有助于全面正确的认识机械结构对称破缺,有助于系统科学的应用结构对称破缺,在一定程度上丰富和推进了机械对称性理论的研究。
[Abstract]:Structural symmetry breaking is a common and interesting phenomenon in the evolution of product structure. In original design, the application law and method of structure symmetry and symmetry breaking can be used scientifically, differently and purposefully for designers to realize product function and improve product performance. Meet design constraints to provide systematic guidance. In the improvement design and the optimization design, the different efficacy of symmetry and symmetry broken structure and the change of the degree of symmetry of mechanical product structure bring about the law of efficacy change, Designers can be guided to achieve product design requirements by changing the symmetry of the structure. As an important part of the theory of mechanical symmetry, the research in this paper will make an important contribution to the establishment of perfect theory of mechanical symmetry. On the basis of deeply analyzing the existence and current research situation of symmetry breaking in various fields, the paper expounds the theory of mechanical symmetry breaking from the following aspects: 1. Establish a perfect conceptual classification system of symmetrical breaking of mechanical structures. In this paper, the mechanical structure examples of symmetry breaking are collected, classified and established, and the breaking forms and breaking degree of the symmetry elements, such as symmetry main body, symmetric component, symmetric datum and symmetric operation, are studied. On the basis of this, a set of relatively perfect concept system of symmetrical breaking of mechanical structure is established. 2, the breaking degree evaluation model of symmetrical breaking of mechanical structure is established. A set of evaluation algorithm is designed to calculate the breaking degree of mechanical structure symmetry breaking, which is used to distinguish the symmetry of mechanical mechanism from symmetric breaking. The established evaluation algorithm is based on the analysis of variance of single factor and calculates the breaking quantity of symmetry elements. The greater the result of the calculation, the lower the degree of symmetry, the greater the result of calculation, the lower the degree of symmetry. The design knowledge of symmetry breaking applied in mechanical product design is summarized. Based on the analysis of a large number of examples, this paper systematically studies the function and performance evolution of mechanical symmetry structure when its symmetry degree changes, and excavates the design knowledge with certain universality and practicability. Further expand the scope of application of symmetrical breaking knowledge. 4, study the application method of mechanical structure symmetry breaking. Through enumerating examples, the application principle and application method of symmetrical broken design knowledge in mechanical design are compared and studied, and the similarities and differences of their respective application rules and application scope are clarified. The application methods of some mechanical structure symmetries in the realization of common design requirements are given, which provide guidance for the practical application of structural symmetry breaking. This paper focuses on the symmetrical breaking of mechanical structure, systematically studies the existing form of structural symmetry breaking in mechanical system, and summarizes the variation and function of symmetry degree of symmetry structure. Based on the design knowledge of performance evolution relation, some application methods of mechanical structure symmetry breaking are established. The research results of this paper are helpful to fully and correctly understand the symmetry breaking of mechanical structure, and to the application of system science, it enriches and advances the research of the theory of mechanical symmetry to a certain extent.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH122

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