Assembly Error Stack-up Analysis And Optimum Tolerancing For Aircraft Assembly

In the process of design and manufacture of aircraft, it is very important that assembly tolerance is practically designed to meet some requirements from aircraft's performance, manufacture, assembly, cost, quality, and so on. The good tolerancing can improve assembly performance, decrease manufacturing cost, and improve manufacturable ability. This dissertation researchs the key technologies and methods on assembly error stack-up analysis and optimum tolerancing for aircraft assembly based on Gragh Theory. Thereinto, assembly tolerance modeling approach based on key features (KF) and Graph is presented; the algorithm gaining assembly dimension chain is researched; we build the self-adapting matching model between assembly tolerance and assembly performance; the integrated and optimum algorithm of assembly tolerancing for multi-objects is presented; and lastly assembly tolerancing sub-system is designed and developed. In the whole dissertation, an example about a subassembly of certain aircraft is used to prove that the methods and theories are correct and useful. The key research works covered in the dissertation are as follows.Firstly, I analyze the relationships between design, process, manufature, assembly and assembly tolerancing. Then I discuss the research backgrounds and significances. On the basis of analyzing the actuality of internal and overseas researches on tolerancing, the dissertation presents the key unfathomed problems about assembly tolerancing for aircraft. And an example is introduced to prove the following methods and the outline of the dissertation.The desired requirements of a tolerance model for part are: completeness, compatibility, computability and validity. We aim to achieve these requirements in a way different from former researchers. Former researchers dealt with dimension tolerance, form tolerance and position tolerance separately. So chapter 2 presents assembly tolerance modeling approach based on KFs and Graph Theory. A unified tolerance model that deals with these three tolerances is built simultaneously. KFs include point KF, line KF and plane KF. I build a meta-tolerance model with five...