Sheet Metal Joint Configurations and Their Variation Characteristics

Abstract

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.