Support Wing Margin Assembly Tolerance Analysis Technique

Aircraft is a kind of special product that requires strict veracity of assembly. Error is the primary factor that affects assembly and manufacturing veracity. Tolerance restricts manufacturing error of part, and allowance redeems the error that comes into being in the process of product assembly. By means of calculus and computer-simulation, tolerance analysis technique for zero-allowance assembly can effectually solve problems during assembly and maintenance. This thesis studies tolerance analysis technique for zero-allowance assembly, and its application in assembly process of one aircraft's airfoil.The main contents of the thesis are as follows:1) Made a systematic and comprehensive analysis on the technical and applicative requirements of tolerance analysis and synthesis during the process of aircraft's life cycle.2) Based on the theory of hill's zero-allowance assembly, proposed concepts and methods for aircraft's zero-allowance assembly.3) Analyzed the characteristics and disadvantages of tolerance modeling technique and aircraft assembly in common use. Presented a method for tolerance modeling, namely 'tolerance modeling supporting airfoil's zero-allowance assembly'. Then tolerance semantic information model for airfoil's zero-allowance assembly is presented. This model includes three kinds of information: constraints between assembly component, affiliation relation between inherited assembly components and allowance, dimension and tolerance information about part and components.4) Based on tolerance semantic information model for zero-allowance assembly, presented an algorithm that can generate assembly tolerance chain. The assembly tolerance-chain is calculated using dimensional simplifying methodand differential coefficient method. Analyzed the influence of concerted chain modification on assembly tolerance-chain. Derived the formula for maximal quantity of repair computation.5) Based on CATIA V5 CAD Software and CAA FOR CATIA V5 Toolbox, designed and developed a tolerance analysis prototype system for airfoil's zero-allowance assembly.