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  • 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.
21

A modular upper bound method for the analysis of metal forming problems /

Ju, Kuang-shi January 1975 (has links)
No description available.
22

Statistical analysis of quality of surface finish in milling operations

Hasham, Husain Ali. January 1964 (has links)
Call number: LD2668 .T4 1964 H34 / Master of Science
23

The metalworking industry in Iran in the early Islamic period

Allan, James W. January 1976 (has links)
Although there are a few general surveys of early Islamic metalwork, and numerous detailed studies of particular objects or object groups, no comprehensive study of the metalworking industry in Iran in early Islamic times has yet been written. This thesis aims to provide that study first by assembling as much as possible of the basic information on metalworking in Iran from the Islamic conquests to the mid 13th century and then by using it to draw some general conclusions about the range and history of Iran's metalworking industries at this time. The primary sources used are the references to metals and metalworking in early Islamic literature and the surviving objects. For technical information and for select vocabularies of the relevant Arabic and Persian terminologies the technical treatises of al-Hamdānī, al-Birūnī, Naṣīr al-Dīn Ṭūsī, and Abū'l-Qāsim al-Kāshānī have been particularly exploited. For the names and functions of particular objects or object groups a range of Arabic non-technical works has been searched. For the gazetteers and general discussions of metal sources Arabic and Persian geographical works have been utilised. The objects catalogued and discussed here include all the published pieces known to the author, together with unpublished objects in the British Museum, the Victoria and Albert Museum, the Ashmolean Museum (including Sirāf excavation material), the Musée du Louvre in Paris (including Susa excavation material), the Museum für Islamische Kunst Berlin-Dahlem, the StaatlicheMuseum in East Berlin, the Museum für Kunst und Gewerbe in Hamburg, the Philadelphia University Museum (including the Rayy excavation material), the Walters Art Gallery, the Freer Gallery of Art, the Metropolitan Museum of Art (including the Nīshāpūr excavation material), and the Boston Museum of Fine Arts. All objects have been arranged in groups on the basis of metal, function, and form, and catalogued accordingly, and an overall dating and provenancing for each group has been established through reference to their decoration, including inscriptions where relevant, and archaeological data. Additional use has been made of analyses undertaken by the Metropolitan Museum of Art, the British Museum, the Musee du Louvre, and the Ashmolean Museum, plus a limited number of other published analyses: all these are included in a single Table.
24

Development of an integrated package for the analysis of hot and cold rolling of strips and sheets

Joshi, Alhad A. January 1989 (has links)
Thesis (M.S.)--Ohio University, June, 1989. / Title from PDF t.p.
25

Computer modeling of complex metal forming processes using the upper bound elemental technique (UBET) and modified upper bound elemental techniqeu (MUBET) /

Al-Mohaileb, Mazyad M. January 2004 (has links)
Thesis (Ph. D.)--Ohio University, March, 2004. / Includes bibliographical references (leaves 140-148).
26

Effects of rolling conditions on texture and microstructure development in [alpha] brass

Chen, Yongjin., 陳永進. January 2000 (has links)
published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy
27

Diagnosis of sheet metal forming processes based on thermal energy distribution: 3D reconstruction.

January 2005 (has links)
Ng Yiu Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 110-114). / Abstracts in English and Chinese. / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Diagnosis concept based on thermal energy distribution --- p.6 / Chapter 1.1.1 --- A cup drawing example --- p.8 / Chapter 1.2 --- Need for 3D infrared thermal distribution measurement --- p.10 / Chapter 1.3 --- Outline of the Thesis --- p.11 / Chapter 2. --- Approach --- p.15 / Chapter 2.1 --- Similarity and extreme temperature analysis --- p.15 / Chapter 2.2 --- Thermodynamics for FEA in sheet metal stamping --- p.17 / Chapter 2.3 --- Acquisition of 3D thermal distribution --- p.20 / Chapter 3. --- Implementation of the Diagnosis System --- p.23 / Chapter 3.1 --- Thermograph acquisition --- p.23 / Chapter 3.2 --- Diagnosis system setup --- p.24 / Chapter 3.3 --- Perspective camera model --- p.25 / Chapter 3.4 --- System calibration --- p.27 / Chapter 3.4.1 --- LEDs calibration board --- p.27 / Chapter 3.4.2 --- Net-and-board calibration box --- p.29 / Chapter 3.5 --- Reconstruction algorithm --- p.33 / Chapter 3.6 --- Summary --- p.37 / Chapter 4. --- Consistency from Different Viewpoints --- p.38 / Chapter 4.1 --- Summary --- p.42 / Chapter 5. --- Visual Reconstruction of Objects --- p.44 / Chapter 5.1 --- Visual camera calibration --- p.45 / Chapter 5.2 --- Results --- p.49 / Chapter 5.2.1 --- "Cartoon model ""SiuSun""" --- p.49 / Chapter 5.2.2 --- Stamping disc --- p.51 / Chapter 5.3 --- Summary --- p.53 / Chapter 6. --- Thermal Distribution Reconstruction of Stamping Workpieces --- p.54 / Chapter 6.1 --- Infrared camera calibration --- p.54 / Chapter 6.2 --- Results --- p.57 / Chapter 6.2.1 --- Air conditioner cap --- p.57 / Chapter 6.2.2 --- Deep drawing cup --- p.59 / Chapter 6.2.3 --- Stamping cylinder from KS Factory --- p.61 / Chapter 6.3 --- Summary --- p.65 / Chapter 7. --- Infrared Camera on a Robotic Arm --- p.66 / Chapter 7.1 --- Robotic arm system setup --- p.67 / Chapter 7.2 --- System calibration --- p.68 / Chapter 7.3 --- Results --- p.77 / Chapter 7.3.1 --- Image sequence from horizontal viewpoints --- p.77 / Chapter 7.3.2 --- Image sequence from inclined viewpoints --- p.80 / Chapter 7.3.3 --- Image sequence from arbitrary viewpoints --- p.83 / Chapter 7.4 --- Comparison of the three different viewpoints --- p.85 / Chapter 7.5 --- Summary --- p.87 / Chapter 8. --- Compensation of Temperature Fade-out Problem --- p.88 / Chapter 8.1 --- Causes of temperature fade-out --- p.88 / Chapter 8.2 --- Solutions --- p.90 / Chapter 8.3 --- Summary --- p.91 / Chapter 9. --- Other Applications --- p.92 / Chapter 9.1 --- Automotive industry --- p.92 / Chapter 9.1.1 --- Background --- p.93 / Chapter 9.1.2 --- Experiment and result --- p.94 / Chapter 9.2 --- General heat transfer analysis --- p.97 / Chapter 9.3 --- Summary --- p.98 / Chapter 10. --- Conclusions --- p.99 / Chapter 10.1 --- Summary --- p.99 / Chapter 10.2 --- Future work --- p.104 / Chapter A. --- Transformation Matrices of the System --- p.106 / Bibliography --- p.110
28

A new sheet metal forming system based on incremental punching. / CUHK electronic theses & dissertations collection

January 2010 (has links)
In order to ensure the desirable performance of the machine, dynamic analysis of the machine is necessary. The analysis is conducted by the mean of computer simulation in consideration of applying a large impulsive force. This study validates the machine stability and accuracy. / In order to verify the new mechanics model, numerical and experimental studies are conducted using the new incremental punching system. The final shape and thickness distributions of parts are compared to verify the mechanics model. It is found that the model prediction fits the experiment result well. Forming parameters are also investigated. / In this research, a new incremental forming system based on incremental punching is designed and built. The system consists of a 3-axes CNC platform, a high speed hydraulic cylinder with a hemispherical forming tool, and a PC-based CNC control system. The hydraulic system provides the forming force to deform the sheet metal with constant stokes, while the CNC system positions the part. When forming a part, the forming tool punches the sheet metal along the given contour of the part punch by punch; when one layer of the part is completed, the forming tool moves down to the next layer; and the process is finished till all layers are completed. The CNC control system works with standard NC code, and hence, is easy to use. / ISMF uses a small generic tool to apply a sequence of operations along the given path to deform the sheet incrementally. These small deformations accumulate to form the final shape of the part. As a result, different parts can be made by the same setup. Despite of some 30 years of research and development, however, ISMF technology is still premature for industrial applications due to the following reasons: The accuracy of the part is limited; the surface roughness is poor; and the productivity is low. This motivates the presented research. / One of the keys to successful application of sheet metal forming is to be able to predict the deformation and the strain/stress of the part incurred during the forming process. Because of the complexity of the ISMF process, it is not possible to derive an analytical method. The alternative is to use Finite Element Analysis (FEA). However, based on our experience, it takes about one week to solve a simple case. A mechanics model is therefore developed. It consists of two steps. The first step is to computer the final shape: the initial geometric surface is obtained using the punch positions; then using the minimum energy principle, the virtual forces drive the nodes of geometric surface to their lowest energy positions, which gives the final shape of the forming part. The second step is to predict the strain and stress distributions. This is done using the inverse Finite Element Modeling (FEM). An in-house computer software is developed using MATLABRTM. / Stamping is one of the most commonly used manufacturing processes. Everyday, millions of parts are formed by this process. The conventional stamping is to form a part in one or several operations with a press machine and a set/sets of dies. It is very efficient but is not cost effective for small batch production parts and prototypes as the dies are expensive and time consuming to make. Recently, with the increasing demands for low-volume and customer-made products, a die-less forming method, Incremental Sheet Metal Forming (ISMF), has become one of the leading R&D topics in the industry. / To evaluate the capability of the presented ISMF process, the formability is studied by the means of theory and experiment. A modified M-K model is proposed for predicting the forming limit of the formed part which is undergoing a very complicated strain path. The maximum forming angle is also investigated by experiments. / Luo, Yuanxin. / Adviser: Ruxu Du. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 121-133). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
29

The effect of cold rolling on the formability of thermoplastics /

Lee, Yew-wing. January 1987 (has links)
Thesis--M. Phil., University of Hong Kong, 1987.
30

Investigation of interlayer burr formation in the drilling of stacked aluminum sheets

Hellstern, Cody. January 2009 (has links)
Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Member: Rhett Mayor; Committee Member: Shreyes Melkote; Committee Member: Steven Danyluk. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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