Using Acoustic Emission Measurements for Ice-Melting Detection

Abstract

Aircraft operators being faced with water accumulation in fuel tanks on a daily basis and are looking for reliable detection systems to determine the remaining amount of accumulated ice during maintenance after flight. Using such a technology, an increase in the safety and efficiency of the aircraft operation would be possible in this highly competitive market. This article presents the use of the Acoustic Emission Technique (AE) for the reliable and non-invasive monitoring of the melting of ice in fuel tanks. This technology is in principle based on the fact that a phase transition comes frequently along with stress relaxation that can be used for monitoring the process. Therefore, the melting of water can, in essence, be monitored with AE without accessing the ice directly. The analysis of the AE signals has been carried out in the time domain since it was the melting of ice needed to be monitored as a function of temperature rise time. The insights presented in this paper can possibly lead to new technologies for ice detection, especially in remote areas that are not easily accessible with other techniques.

In-line monitoring of cryogenic three-point bending test of fiber-reinforced composites using acoustic emission

“…11 A well-established method for in-line monitoring and damage analysis of composite materials is acoustic emission (AE). 12,13 In general, AE is a passive structure-borne sound method widely used for non-destructive testing, structural health monitoring, and condition monitoring of different material classes and processes, e.g., chemical reactions and crystallization processes, [14][15][16] icing processes, 17 injection molding, 18,19 composite structures, 20,21 and cryogenic cycling. [22][23][24] Throughout the monitoring of structural components, the AE method detects transient waves emitted by the release of energy due to microstructural changes.…”

“…The evaluation of extracted AE features, such as the maximum amplitude, peak frequency, and energy, gives the possibility for characterization. 13,17,27,28 Boominathan et al 29 studied the damage mechanisms in unidirectional and cross-ply carbon fiber-based polymer laminates with 3-point bending tests. They correlated matrix cracking, delamination, and fiber failure with the frequencies 60−100 kHz, 120−210 kHz, and 200−350 kHz.…”