Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Bibliography: leaf 47. / by John Christopher Moran. / B.S.

Tolerance analysis is a major link between design and manufacturing. An assembly or a part should be designed based on its functions, manufacturing processes, desired product quality, and manufacturing cost. Assembly tolerance analysis performed at the design stage can reduce potential manufacturing and assembly problems. Several commonly used assembly tolerance analysis models and their limitations are reviewed in this research. Also, a new assembly tolerance analysis model is developed to improve the limitations of the existing assembly tolerance analysis models. The new model elucidates the impact of the flatness symbol (one of the Geometric Dimensioning and Tolerancing (GD&T) specification symbols) and reduces design variables into simple mathematical equations. The new model is based on beta distribution of part dimensions. In addition, a group of manufacturing variables, including quality factor, process tolerance, and mean shift, is integrated in the new assembly tolerance analysis model. A computer integrated system has been developed to handle four support systems for the performance of tolerance analysis in a single computer application. These support systems are: 1) the CAD drawing system, 2) the Geometric Dimensioning and Tolerancing (GD&T) specification system, 3) the assembly tolerance analysis model, and 4) the tolerance database operating under the Windows environment. Dynamic Data Exchange (DDE) is applied to exchange the data between two different window applications, resulting in improvement of information transfer between the support systems. In this way, the user is able to use this integrated system to select a GD&T specification, determine a critical assembly dimension and tolerance, and access the tolerance database during the design stage simultaneously. Examples are presented to illustrate the application of the integrated tolerance analysis system. / Graduation date: 1995

Thesis (Ph. D.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains xiv, 118 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 109-118).

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: Fixture stiffness matrix; Jacobian matrix; kinetic model; geometric model; fixture design verification; stability analysis; tolerance analysis; tolerance assignment. Includes bibliographical references (p. 92-97).

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2003. / Includes bibliographical references (p. 93-95).

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Computer models of the geometry of the real world have a tendency to assume that the shapes and positions of objects can be described exactly. However, real surfaces are subject to irregularities such as bumps and undulations and so do not have perfect, mathematically definable forms. Engineers recognise this fact and so assign tolerance specifications to their designs. This thesis develops a representation of geometric tolerance and uncertainty in assemblies of rigid parts. Geometric tolerances are defined by tolerance zones which are regions in which the real surface must lie. Parts in an assembly can slop about and so their positions are uncertain. Toleranced parts and assemblies of toleranced parts are represented by networks of tolerance zones and datums. Each arc in the network represents a relationship implied by the tolerance specification or by a contact between the parts. It is shown how all geometric constraints can be converted to an algebraic form. Useful results can be obtained from the network of tolerance zones and datums. For example it is possible to determine whether the parts of an assembly can be guaranteed to fit together. It is also possible to determine the maximum slop that could occur in the assembly assuming that the parts satisfy the tolerance specification. Two applications of this work are (1) tolerance checking during design and (2) analysis of uncertainty build-up in a robot assembly plan. I n the former, a designer could check a proposed tolerance specification to make sure that certain design requirements are satisfied. In the latter, knowledge of manufacturing tolerances of parts being manipulated can be used to determine the constraints on the positions of the parts when they are in contact with other parts.