Jeff Dabling, Sandia National Labratories
Presented June 14, 2001 at the ADCATS 2001 Conference

Previous ADCATS research developed a method for analyzing variation in 2D assemblies using commercial kinematic software.  Using a velocity/variation analogy, Equivalent Variational Mechanisms (EVMs) were developed to allow a kinematic model to be modified to introduce dimensional variation.  Following appropriate modeling procedures, the assembly variation can be calculated using standard kinematic equations.

This presentation describes the work of expanding the 2D research to 3D assemblies.  In addition, similar techniques are described for incorporating geometric variation.  Geometric variation can contribute significantly to assembly variation through parallelism, perpendicularity, profile, and related form issues. 

With these newly developed EVMs, a 3D kinematic assembly can be modified to allow dimensional and geometric variation to be included in a tolerance analysis using commercial software.  With the wide availability and use of kinematic/dynamic analysis software as compared to variation analysis software, these methods allow complicated 2D and 3D tolerance analysis to be performed by a wide segment of industry that previously had no such capabilities.

Bio
Jeff Dabling is completing an MS degree in Mechanical Engineering at Brigham Young University as a graduate student of Dr. Ken Chase.  His thesis involves the incorporation of dimensional and geometric variation in 3D mechanical assemblies using kinematic equations.  He has accepted a position at Sandia National Laboratories in Albuquerque, NM, and will be involved in the analysis and design of mechanisms.