Similarity measures for mid-surface quality evaluation

Mid-surface models are widely used in engineering analysis to simplify the analysis of thin-walled parts, but it can be difficult to ensure that the mid-surface model is representative of the solid part from which it was generated. This paper proposes two similarity measures that can be used to evaluate the quality of a mid-surface model by comparing it to a solid model of the same part. Two similarity measures are proposed; firstly a geometric similarity evaluation technique based on the Hausdorff distance and secondly a topological similarity evaluation method which uses geometry graph attributes as the basis for comparison. Both measures are able to provide local and global similarity evaluation for the models. The proposed methods have been implemented in a software demonstrator and tested on a selection of representative models. They have been found to be effective for identifying geometric and topological errors in mid-surface models and are applicable to a wide range of practical thin-walled designs

Economical and technological study of surface grinding versus face milling in hardened AISI D3 steel machining operations

[EN] This work deals with the technological and economic considerations required to select face milling vs. surface grinding operations in the manufacture of hardened steel flat surfaces for dies and moulds. In terms of technological considerations, factors such as component geometry, material and surface quality (dimensional tolerance and surface finish) are taken into account. The economic considerations include the cost of machine depreciation, labour and consumables (cutting tools in face milling vs. grinding wheels and dressing tool in surface grinding). A case study is presented based on the prismatic components in ceramic tile moulds and their associated manufacturing operations. Surface grinding and face milling experimentation was conducted on cold work steel AISI D3 (with hardness of 60 HRC) with aluminium oxide grinding wheels and coated tungsten carbide cutting tool, respectively. Technological attributes and economics of face milling are compared with surface grinding of this type of mould components. The main conclusion is that face milling with chamfered edge preparation in coated tungsten carbide tools is a competitive process, compared with surface grinding, in terms of product quality and economics.The research team would like to acknowledge the main support of the Caja Castello-Bancaixa Foundation and Universitat Jaume I, which support the project: "Integration of Planning, Execution and Control of High Speed Machining Operations in Collaborative Engineering Environments: Application in Moulds for Tile Industry", the ceramic tile mould company MACER S.L., and would like to extend their gratitude to Roberto Menendez, student of industrial engineering. Particular thanks go to the Programme Alssan: European Union Programme of High Level Scholarships for Latin America (scholarship no. E04D030982MX). Additional support was provided by Tecnologico de Monterrey through the research group in Mechatronics and Intelligent Machines (http://cidyt.mty.itesm/cimec).Vila Pastor, C.; Siller, H.; Rodríguez, C.; Bruscas Bellido, G.; Serrano, J. (2012). Economical and technological study of surface grinding versus face milling in hardened AISI D3 steel machining operations. International Journal of Production Economics. 138(2):273-283. doi:10.1016/j.ijpe.2012.03.028S273283138

Nostalgia, the Specter of Ideals, and the Fall of the USSR: A View from the United States

This thesis attempts to interrogate questions of nostalgia, asking how former citizens of the USSR remember the collapse of the Soviet Union as well as state discourse put forth by the Soviet regime. I ask how people perceive this discourse "which was intended to describe the socio-political reality of the Soviet Union and justify the actions of the state" as well as how they perceive the ideals that stand behind this discourse. Finally, I consider what these perceptions can reveal about the presence or absence of nostalgia for the Soviet period. In order to investigate these questions, I conducted interviews with a number of people who were born in the USSR and who moved to the United States at some point in the '90s, focusing on memories of the school system as well as of the Chernobyl nuclear disaster. My thesis concludes that those whom I interviewed are relatively unnostalgic for this period of their lives, in some cases being quite glad to be rid of it, in other cases accepting the bad with the good and moving on

Design for manufacturability handbook, 2nd ed./ edit.: James G. Bralla

xxvii, 1.3-9.31 hal.: ill, tab.; 23 cm