In sheet metal assembly, joints are designed to facilitate welding the parts. The three basic joints used in sheet metal assemblies are lap (slip) joints, butt joints, and butt-lap (corner) joints. Each joint configuration has its own variation characteristics. However, the currently available variation analysis methods, such as worst case analysis, root sum squares, etc., are not applicable to deformable sheet metal because they are based on rigid bodies. This paper analyzes the variation characteristics of simple assemblies constructed from the three basic joints, using Mechanistic Variation Simulation. Mechanistic Variation Simulation combines engineering structural models with statistical analysis in predicting deformable sheet metal assembly variation. Furthermore, the variation characteristics of the boxes constructed from the three basic joints are also evaluated. The developed models and analysis provide an improved understanding of sheet metal product design and process design.

1.
Chase, K. W., and Parkinson, 1991, “A Survey of Research in the Application of Tolerance Analysis to the Design of Mechanical Assemblies,” Research in Engineering Design, No. 3, pp. 23–37.
2.
Craig, M., 1989, “Managing Variation by Design Using Simulation Methods,” Failure Prevention and Reliability, ASME Publ. No. DE-Vol. 16, pp. 153–163.
3.
Early, R., and Thompson, J., 1989, “Variation Simulation Modeling—Variation Analysis Using Monte Carlo Simulation,” Failure Prevention and Reliability, ASME Publ. No. DE-Vol. 16, pp. 139–144.
4.
Fortini, E. I., 1967, Dimensioning for Interchangeable Manufacturing, Industrial Press, New York. p. 48.
5.
Greenwood
W. H.
, and
Chase
K. W.
,
1988
, “
Worst Case Tolerance Analysis with Nonlinear Problems
,”
ASME JOURNAL OF ENGINEERING FOR INDUSTRY
, Vol.
110
, Aug., pp.
232
235
.
6.
Greenwood
W. H.
, and
Chase
K. W.
,
1989
, “
Root Sum Squares Tolerance Analysis with Nonlinear Problems
,”
ASME JOURNAL OF ENGINEERING FOR INDUSTRY
, Vol.
112
, Nov., pp.
382
384
.
7.
Liu
S. C.
, and
Hu
S. J.
,
1997
, “
Variation Simulation for Deformable Sheet Metal Assemblies Using Finite Element Methods
,”
ASME JOURNAL OF ENGINEERING FOR INDUSTRY
, Vol.
119
, pp.
368
374
, August.
8.
Liu
S. C.
,
Lee
H.-W.
, and
Hu
S. J.
,
1995
, “
Variation Simulation for Deformable Sheet Metal Assemblies Using Mechanistic Models
,”
Trans. of NAMRI
, Vol.
XXII
, May, pp.
235
240
.
9.
MSC/NASTRAN, 1991, User’s Manual (Version 67), MacNeal-Schwendler Corporation, Vol. 1 & Vol. 2.
10.
Natale
T.
, and
Irving
B.
,
1992
, “
Automakers Set the Pace for Spot Welding the New Galvanized Steel
,”
Welding Journal
, Vol.
71
, March, pp.
47
52
.
11.
Spotts, M. F., 1978, “Dimensioning Stacked Assemblies,” Machine Design, Apr., pp. 60–63.
12.
Skalmierski, B., 1979, Mechanics and Strength of Materials, Elsevier Scientific Publishing Company, New York.
13.
Takezawa, N., 1980, “An Improved Method for Establishing the Process-Wise Quality Standard,” Reports of Statistical Application Research, Union of Japanese Scientists and Engineers (JUSE), Vol. 27, No. 3, September, pp. 63–76.
14.
VSA, 1990, Variation Simulation Analysis Software, Applied Computer Solutions, St. Clair Shores, Michigan, User’s Manual Vol. 1 and 2.
This content is only available via PDF.
You do not currently have access to this content.