Identifying deviation in aircraft structures using variation simulation

Abstract

Although widely used in the automotive industry, Variation Simulation has only been in use in the aerospace industry for a relatively short period of time. The use of variation simulation in the aero-industries is by far and large, mainly by the large airframe manufacturing companies. Variation Simulation can be used to identify the variation and deviation in complex aircraft assemblies, where using traditional methods analysis can become very difficult, if not impossible. Typically variation analysis is performed by tolerance stack analysis using manual methods such as Root Sum Squares statistical tolerance. This method assumes the variation in all detail parts vary randomly, following a centred Normal Distribution with a ±3σ range. This paper outlines a brief study undertaken to identify how statistical tolerancing using Uniform Distribution may be more suitable than using Normal Distribution when working with simulation models.

Keywords:

• Complex assemblies
• variation analysis
• variation simulation
• tolerance stacking analysis
• root mean square tolerance analysis
• normal distribution
• and uniform distribution

Acknowledgements

Dimensional Control Systems Inc. Troy, Michigan, USA. Tecnico Logix Ltd, Belfast, UK. UTAS Aero Structures, Chula Vista, California, USA.