Numerical Analysis of Influencing Factors and Capability for Thermal Wave NDT in Liquid Propellant Tank Corrosion Damage Detection

Abstract

Due to the disadvantages of traditional NDT methods for liquid propellant tank corrosion detection, Thermal Wave Nondestructive Testing (ITWNDT) technology was applied. The heat exchange process of thermal wave in corrosion tank was simulated by the numerical method. Parameters of TWNDT as the best detection time (t best ), the maximum surface temperature difference (ΔT max ), and the temperature difference holding time (τ ΔT>0.1 ) were discussed as the targets. Based on these parameters, factors influencing the detection results of tank materials, dressed liquid (also considered as the corrosion product), pit characters (depth and size), heat flux and thermal excitation time length (pulsed width), environmental conditions and other factors were analyzed. Simulation results show that ITWNDT can identify the defect depth, size and position rapidly and effectively. Material properties of the tank were influencing the t best , ΔT max and τ ΔT>0.1 , while the dressed liquid, thermal excitation parameters and the conditions of environment do not influence the t best . Pit characters of the depth and size have close relationship with t best and ΔT max , therefore, for a tank with certain material and certain liquid dressed in, the pit corrosion damage can be accurately evaluated.

The aircraft structural elements corrosion study using strain gauge method and pulse video thermography

“…The application of thermography and other contemporary devices for control and non-destructive monitoring of the structure condition represent an advanced technique in the field of on condition maintenance and make a transition from conventional, ultrasound methods towards integrated systems for Structural Health Monitoring (SHM) [6][7][8]. Contemporary thermal imaging cameras [9][10][11], together with the special software for thermal image processing and analysis, can be applied on a mass scale in aviation industry using the Infrared (IR) thermography method. Except PVT, some other methods of IR Thermography can be used for NDT&E, such as Lock-in Thermography (LT) and Pulsed Phase Thermography [12][13][14][15][16][17].…”