• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Planning for Curved-Surface Milling and Surface Profile Measurement by Taguchi Method

Wang, Hsueh-o 30 June 2006 (has links)
ABSTRACT This research uses Taguchi Method, combined with Computer Aided Design and Manufacturing, processing the work piece into the saddle type. Next, diverse sampling methods are applied to measure the profile of surface with Coordinate Measuring Machine, with an aim to analyzing the main factors that influence cutting and seeking the last conditions for cutting out the curved surface; in addition, I will probe into the contribution rate of each factor which influences the precision during the process of measurement. The following results of this research are expected to be offered to the circles of vocational education as a basis of processing and measuring instruction. In this way, it will not take too much time to try and error and therefore, the practice course can be more efficient. 1. With reference to the documents that are focused on the factors affecting the cutting, this thesis, by means of Taguchi Method, shows that during the process of cutting saddle-type curved surface, the rotating speed of the axle is the most influential, whose contribution rate is 59.38%. 2. Since most documents are on circles, balls or cone objects, this thesis will aim at the measurement of saddle-type curved surface, with an intention to further the measuring technique. 3. It is found that as to the saddle-type curved surface, random sampling can get the profile of surface with minimal errors, and has no such trouble as using HSS or LHS, which can reduce time and cost. 4. In the experiment of Taguchi Method, according to analysis of variance, the influence of the sampling area is the greatest while the choice of sampling method only contributes to 3.46%.
2

Méthodologie de caractérisation et de conception d'un outil coupant à plaquettes amovibles pour l'usinage de matériaux composites aéronautiques : Application aux opérations de surfaçage / Aeronautic composites face milling : characterization and designing methods for cutting tools with indexable inserts

Morandeau, Antoine 07 December 2012 (has links)
Les composites utilisés dans l'industrie aéronautique sont hétérogènes. Ils sont composés d'une matrice polymère souple et ductile et d'un renfort dur et fragile. Les différentes phases ainsi que l'anisotropie du matériau peuvent rendre l'usinage de ces matières, difficile. Deux problèmes majeurs peuvent être rencontrés lors de l'usinage : garder l'intégrité de la matière usinée et réduire l'usure de l'outil de coupe. Les niveaux de qualité demandés dans le secteur aéronautique imposent une coupe sans défaut, ces derniers pouvant entrainer une altération ultérieure de la pièce. Les principaux défauts rencontrés sont : le délaminage des plis, la surchauffe de la résine, les plis non coupés francs ou l'écaillage. / Aeronautic composites are inhomogeneous and most often consist in two distinctly phases. The reinforcement fibres are relatively hard and brittle whereas the matrix is soft and ductile. The anisotropy causes some severe challenges when machining composites. People in the field often experience a trade-off between two main problems ; on one hand, keeping the composite parts integrity and quality, and on the other hand, reducing the wear of the cutting tools. The quality level required in aeronautic applications imposes a high quality cut of machined parts. Common defects that may occur during machining of these materials are delamination, overheat of the resin, uncut fibres, and fibre pull-out.

Page generated in 0.0529 seconds