Measurement Uncertainty of a Coordinate Measuring Machine Applied to a Thin-Walled Aircraft Structure in Relation to the Assessment of Dimensional and Shape Accuracy

This paper presents the estimation of measurement uncertainty of a CMM (coordinate measuring machine) as applied to a thin-walled aircraft structure in relation to the assessment of its dimensional and shape accuracy. The current tendency to minimize the mass of components in aviation leads to an increasing use of pocket structures with thin walls. High-performance techniques such as HSC (High Speed Cutting) and HPC (High Performance Cutting) are used for their production. In the case of thin-walled structures, a significant problem is the dimensional and shape accuracy, which is very difficult to maintain. The tests were carried out on a test element made of EN AW-2024 T351 aluminum alloy, which is widely used in the aviation industry. A coordinate measuring machine was used to assess the dimensional and shape accuracy. Additionally, the measurement uncertainty was also analyzed.

I. Introduction

The engineering systems of such complexity as aircraft require a specific approach both to their structural design and the technology of manufacturing their individual components. According to their significance for the correct, reliable and safe operation of the aircraft, these components are divided into two functional groups [1]: