Theoretical and Experimental Evaluation of a Real-Time Corrosion Monitoring System for Measuring Pitting in Aircraft Structures

Abstract

This paper presents the theory and experimental validation of Analatom’s Structural Health Management (SHM) system for monitoring corrosion. Corrosion measurements are acquired using a micro-sized Linear Polarization Resistance (uLPR) sensor. The uLPR sensor is based on conventional macrosized Linear Polarization Resistance (LPR) sensors with the additional benefit of a reduced form factor making it a viable and economical candidate for remote corrosion monitoring of high value structures, such as buildings, bridges, or aircraft.

A series of experiments were conducted to evaluate the uLPR sensor for AA 7075-T6. Test coupons were placed alongside Analatom’s uLPR sensors in a series of accelerated tests. LPR measurements were sampled at a rate of once per minute and converted to a corrosion rate using the algorithms presented in this paper. At the end of the experiment, pitdepth due to corrosion was computed for each sensor from the recorded LPR measurements and compared to the average pit-depth measured on the control coupons. The results demonstrate the effectiveness of the sensor as an efficient and practical approach to measuring pit-depth for AA 7075-T6.