PSI - Issue 5

Smail Sahnoun et al. / Procedia Structural Integrity 5 (2017) 1065–1071 Asseya El-amiri et al./ Structural Integrity Procedia 00 (2017) 000 – 000

1069

5

3

2

a

e

e

17, 60. 1,96 e  

60, 72.

55, 72.





0





3

2

4

a

e

e

1, 08. 0,12 .10 e  

3, 72.

3, 42.

 



1

3

2 5, 25. 1, 66. 0,18).10 e e  

6

a

e

( 5, 72.





2

This model is very important in non-destructive testing, It makes it possible to determine the depth of the hidden rust from the surface temperature of the corroded bolt.

3.2. Study of the rust thickness’s effect

To demonstrate the influence of the thickness of the hidden rust layer on the surface temperature of the inspected corroded bolt, we considered four layers, which have a cylindrical shape, of rust placed under the surface as shown in Fig.4. In this study, we have fixed the rust depth at 1cm for the following thicknesses 0.5cm, 1cm, 1.5cm, 2cm for the case of the large bolt. As for the second bolt, the depth of the rust was fixed at 0.1cm and the thicknesses chosen are 0.05cm, 0.1cm, 0.15cm, and 0.2cm. We have plotted the temperature variations along the axis A3A4 for each case in Fig.5. It is found that the temperature of rusty areas is higher than that of healthy areas. In addition, the curves are more distinct when the thickness of the rust is important and the curve on the fault zone becomes more convex.

A3 A4

Fig.4.

Diagram illustrating the variation of the rust thickness between the screw and the nut

a

b

Fig.5. (a) The temperature evolution along the axis (A3A4) for four different thicknesses in the case of the large bolt; (b) The temperature evolution along the axis (A3A4) for four different thicknesses for the case of the medium sized bolt