Doctoral Dissertations


"The importance of metal forming by extrusion was reviewed. A Finite Element Approach was developed to analyze extrusion processes. A brick type linear element and the Upper Bound theorem were used to analyze the extrusion of a cylindrical billet into a square cross-section prism. A minimization technique for a non-linear functional with linear constraints was developed. Different types of boundary conditions were also formulated. A frictionless extrusion was simulated using the computer program developed. Velocity profiles at different sections of the deforming solid were obtained and an average extrusion pressure was predicted for a given area reduction ratio.

Extrusions from a cylindrical billet into a square cross-section prism were performed for four different area reduction ratios: 1:2.26, 1:2.55, 1:2.97 and 1:3.34. A Beta Press manufactured by Pressure Technology Corporation of America was used. Billets were made from 6061 T 651 Aluminium.

The effect of friction was investigated analytically. Also a brick type quadratic element (20 nodes) was tested successfully using the compression of a short cylinder as an example"--Abstract, page iii.


Davis, Robert L.

Committee Member(s)

Lehnhoff, T. F., 1939-
Ho, C. Y. (Chung You), 1933-1988
Barker, Clark R.
Keith, Harold D. (Harold Dean), 1941-


Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering


United States. Agency for International Development
National Institute of Technology in Saigon


University of Missouri--Rolla

Publication Date



x, 120 pages

Note about bibliography

Includes bibliographical references (pages 47-50).


© 1974 Nguyen Don Phu, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type




Library of Congress Subject Headings

Metals -- Extrusion
Finite element method
Sheet-metal Work

Thesis Number

T 3033

Print OCLC #


Electronic OCLC #


Link to Catalog Record

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