Research On Functional Tolerancing Design Based On Geometrical Product Specification

On the basis of comprehensive analysis for recent research status of computer-aided Tolerancing both in and out of China, binding State Natural Science Foundation of China ("Research on Computer Aided Functional Tolerancing Design Theoretic and Methods Based on Geometrical Product Specification", No.50775204), ("Research on Tolerance Modeling Based on Geometrical Product Specification", No.50505046), Functional Tolerancing Design based on Geometrical Product Specification is studied.In Chapter 1, the state of art on the Geometrical Product Specification, tolerance modeling theories and computer-aided functional tolerance are summarized. The main contents, general structure scheme of this dissertation are given.In Chapter 2, the concepts of feature, constraint are introduced. The geometric constitution of product based on the seven basic invariance classes is analyzed. The tolerance mathematical modeling method based on GPS is studied. The variational geometric constraint matrix and the SDT screw matrix are given. Feature-based Tolerance representation model is given.In Chapter 3, the classification of the assembly orientation node and the principle to determine the sequence of these nodes are studied. Improving assembly oriented graph is put forward by adding the information of the assembly allocation constraints. The method of expression and decomposition for geometrical functional requirement is proposed;In Chapter 4, the concepts of mate tree and datum reference frame are introduced; tolerance specification design method which is used to define the interfaces between parts is studied.The functional tolerance specification design process and the method between geometrical functional requirement and geometrical specification design are disscussed.At last, two examples are provided to validate the method;In Chapter 5, a tolerance specification design system is developed and integrated into SolidWorks2005.An application is given to illustrate the functions of the software;In Chapter 6, the conclusions of the dissertation are summarized and future research of functional tolerance specification design based on the new generation of GPS is prospected.