Detection of corrosion depth in bolts by thermographic model

Several industrial plants suffer from the presence of corrosion in its assembly elements. The hazardous condition of a corroded metal installation is difficult to assess by visual inspection. The existence of rust can cause accidents that have terrible technical and economic consequences. In the context of the safety and security of personnel and metal structures subjected to heavy mechanical or thermal stresses, we propose, in this paper, a mathematical model based on the numerical three dimensional finite elements method which allows to estimate by infrared thermography the depth and the thickness of the hidden corrosion between two elements of steel assembly. The exploitation of the results obtained makes it possible to carry out preventive maintenance to eliminate the hazards before a critical threshold of the dimensions of the hidden rust is reached. We have studied the thermal response of the corroded elements with respect to the size of the hidden rust and we have taken into consideration the size of the assembly elements.