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System variation analysis of MIG welded aluminum structural frames

IP.com Disclosure Number: IPCOM000128032D
Original Publication Date: 1998-Dec-31
Included in the Prior Art Database: 2005-Sep-14
Document File: 4 page(s) / 18K

Publishing Venue

Software Patent Institute

Related People

Painter, Christopher D: AUTHOR [+3]

Related Documents

http://theses.mit.edu:80/Dienst/UI/2.0/Describe/0018.mit.theses/1998-278: URL

Abstract

Variation reduction techniques are developed which explore an entire system for improved quality, rather than a single manufacturing operation. This system-level modeling approach is explored with an example of a complex assembly of aluminum extrusions and castings welded into a structural frame. By making use of modeling techniques such as Finite Element Analysis (FEA) and Design of Experiments (DOE), it can be shown. how this method can also be applied to systems that include complex processes such as welding. Modeling the entire system of manufacturing operations allows key sources of variation and difficult output quality characteristics to be identified. In addition, intermediate tolerances can be determined in relation to the final required output tolerances. Determining intermediate tolerances is a two step process. First, a system of block diagrams are created to clearly outline how variation propagates forward through the system. These block diagram representations are linearized models that map the transformations between the input variations and the output variations of a particular manufacturing operation. Secondly, using the combined transformation matrix of the system, intermediate tolerances, at a particular manufacturing operation can be determined by back-propagating final output tolerances. This provides a means by which design tolerances on the final product can be used in determining the allowable tolerances on Work-In-Progress (WIP) at intermediate manufacturing processes. Thesis Supervisor: Kevin N. Otto Title: Assistant Professor of Mechanical Engineering 2 "It is the supreme art of the teacher to awaken joy in creative expression and knowledge.

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System Variation Analysis of MIG Welded Aluminum Structural Frames

by

Christopher D. Painter B.S., Mechanical Engineering (1995) University of Rochester Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology June 1998
SIGNATURE OF author: [[signature omitted]]

Department of Mechanical Engineering May 14, 1998
CERTIFIED BY: [[SIGNATURE OMITTED]]

Kevin N. Otto Assistant Professor of Mechanical Engineering Thesis Supervisor ACCEPTED BY: [[SIGNATURE OMITTED]]

Ain A. Sonin Chairman, Department Committee on Graduate Students ARCHIVES MASSACHUSETTS INSTITUTE OF TECHNOLOGY LIBRARIES AUG 04 1998

1

Massachusetts Institute of Technology Page 1 Dec 31, 1998

Page 2 of 4

System variation analysis of MIG welded aluminum structural frames

System Variation Analysis of MIG Welded Aluminum Structural Frames

by

Christopher D. Painter

Submitted to the Department of Mechanical Engineering On May 14, 1998 in partial fulfillment of the Requirements for the Degree of Master of Science

ABSTRACT

Variation reduction techniques are developed which explore an entire system for improved quality, rather than a single manufacturing operation. This system-level modeling approach is explored with an example of a complex assembly of aluminum extrusions and castings welded into a structural frame. By making use of modeling techniques such as Finite Element Analysis (FEA) and Design of Experiments (DOE), it can be shown. how this method can also be applied to systems that include complex processes such as welding.

Modeling the entire system of manufacturing operations allows key sources of variation and difficult output quality characteristics to be identified. In addition, intermediate tolerances can be determined in relation to the final required output tolerances. Determining intermediate tolerances is a two step process. First, a system of block diagrams are created to clearly outline how variation propagates forward through the system. These block diagram representations are linearized models that map the transformations between the input variations and the output variations of a particular manufacturing operation. Secondly, using the combined transformation matrix of the system, intermediate tolerances, at a particular manufacturing operation can be determined by back-propagating final output tolerances. This provides a means by which design tolerances on the final product can be used in determining the allowable tolerances on Work-In- Progress (WIP) at intermediate manufacturing processes.

Thesis Supervisor: Kevin N. Otto Title: Assistant Professor of Mechanical Engineering

"It is the supreme art of the teacher to awaken joy in...