A new method of rigid assemblies stochastic 3D tolerance analysis including thermal performance.

• Ano de defesa: 2022
• Autor(a) principal: Umaras, Eduardo
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: 3D tolerance analysis; Custo econômico; Geometric tolerances; Método de Monte Carlo; Monte Carlo method; Multivariate distribution; Processos de fabricação (Engenharia Mecânica); Produção industrial (Otimização); Tolerancia e ajustamento das peças
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/3/3152/tde-07072022-112403/

Positional and orientation tolerances are specified in the components of a mechanical assembly and are of great importance in design, as they affect its quality, reliability, and cost. Tolerance analysis is a method of stacking the tolerances parts of an assembly to achieve an overall value in a given direction. The opposite approach is tolerance synthesis, or allocation, where the tolerances of the components are adjusted through a determined criterion for compliance with design constraints or for optimization purposes, such as cost reduction. The tolerance synthesis is generally performed when the results of a tolerance analysis process do not reach a design constraint requirement. The aim of this thesis is to propose a new method for tolerance analysis in a three-dimensional domain, including manufacturing simulation and consideration of functional thermal effects. A case study involving an internal combustion engine shows the efficacy of the method. Manufacturing simulation based on the Monte Carlo method provides a statistical distribution representation of process variation along a specified tolerance range. This resource can lead to optimization of the tolerance range of the mechanical assembly in each orthogonal direction and can also be a significant aid in design decisions and the selection of manufacturing processes. A feature of the proposed method is the consideration of geometric position tolerances as a function of orientation tolerances. The feature results in great accuracy at a high manufacturing volume. The method is application-oriented and can be applied effectively in the industry.