PSI - Issue 33

M.F.M.O. Rosas et al. / Procedia Structural Integrity 33 (2021) 115–125 Rosas et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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mm and t SI = t SE =2 mm values were always considered. The construction of the models and mesh refinement followed the same principles described in Section 2.3. Fig. 4 schematically shows the outer chamfer (a), inner chamfer (b) and adhesive fillet (c). In the stress analyses that follow, τ avg is the average value of  xy for the respective joint configuration between overlap ends.

Fig. 4. Schematic representation of the outer (a), inner chamfer (b) and adhesive fillet (c) modifications and respective definition of the angles.

3.2.1. Outer chamfer This geometric modification consists in an external chamfer to the adherends. The values of the outer chamfer angle (  ) were 7,5  , 15  , 30  , 45  , 60  and 90  . Fig. 5 (a) shows the σ y/ τ avg stress distributions as a function of the  variation. σ y stress distributions show that the peak stress always occurs at the overlap ends. The adhesive Araldite ® 2015 reports a reduction of σ y/ τ avg from  =45  to  =7.5  . Between  =45  and  =60  there is no significant variation of σ y stresses and, finally, between  =60  to  =90  there is a decrease of σ y peak stresses. According to the obtained results, the highest reduction of the maximum σ y / τ avg , over the reference joint with  =90º, was 45.6% for  =7.5º. Fig. 5 (b) shows the τ xy / τ avg stress distribution curves as a function of  . The results show a decrease of the peak τ xy / τ avg for smaller  . Consequently, the highest value of τ xy / τ avg occurs in the joint without geometrical modifications (  =90  ), showing a reduction of the maximum τ xy / τ avg of 42.7% for  =7.5º, over the joint with  =90  .

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5

4

4

3

2

 y /  avg

 xy /  avg

2

0

1

-2

0

0

0.2

0.4

0.6

0.8

1

0

0.2

0.4

0.6

0.8

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x / L O

x / L O

7.5º

15°

30°

45°

60°

90°

7.5º

15°

30°

45°

60°

90°

a)

b)

Fig. 5.  y (a) and  xy (b) stress distributions in the adhesive as a function of  .

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40

30

P [kN]

20

10

0

0

0.1

0.2

0.3

0.4

0.5

0.6

 [mm]

7.5º

15°

30°

45°

60°

90°

Fig. 6. P -  curves as a function of  .

Fig. 6 shows the P -  curves for the tubular joints bonded with the adhesive Araldite ® 2015, obtained by CZM, for the different  at the overlap ends. It can be found that joint has no significant variation in P m between the different