Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637922
Title: Optimal design of aluminium extrusion dies using a novel geometry based approach
Author: Lin, C.
Awarding Body: University of Wales Swansea
Current Institution: Swansea University
Date of Award: 2005
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Abstract:
Aluminium extrusion is a forming process used for manufacturing straight and long aluminium products. Among all aspects of the process, extrusion die design is the key issue for producing high-quality extrudates. The approaches to design extrusion dies can be broadly classified into three groups; trial and error, empirical based approach and numerical simulation based approaches. To overcome the limitations posed by current available design approaches, a new geometry based methodology has been proposed in this thesis. The new methodology combines design formulae, geometry reasoning technique and optimization algorithm together. In this research work, a new knowledge representation scheme is developed so that historical data can be easily gathered and reused. By using empirical bearing length design formulae with historical data, a new bearing length estimation approach is introduced so that new profiles can be designed based on past good designs. A novel die layout design approach has also been developed and validated. This new method uses bearing length estimation algorithms with maximum bearing length difference to give radial or flat layout for single/multi-hole dies. By using medial axis transform, a set of new geometry reasoning algorithms have been studied. These algorithms give a general and robust way to analyze two-dimensional geometry shapes. A brand-new die profile categories have been proposed to avoid the drawbacks held by current classification. A new algorithm and a set of new classifying criteria have been introduced. Based on medial axis transform and geometry reasoning technique, extrusion die profiles can be classified into different category correctly and efficiently. This research work shows that all the proposed approaches give several feedback paths in extrusion die design process.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.637922  DOI: Not available
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