PSI - Issue 61

G.J.C. Pinheiro et al. / Procedia Structural Integrity 61 (2024) 71–78 Pinheiro et al. / Structural Integrity Procedia 00 (2019) 000 – 000

75 5

2

2

2

2

n       0 n t t  

n   n         0

s s   t   t 0

s      0 s 

or

f

f

=

+

=

+

(3)

.

   

   

For the MAXS, MAXE, QUADS, and QUADE criteria, crack was set to propagate along the x-axis, aligning with the a dhesive layer’s length. All six of the criteria mentioned are satisfied when f reaches a value of unity, signifying the initiation of damage. To model damage growth, the phantom nodes approach was employed, described in the work of Campilho et al. (2011b). Initially, a linear softening law was adopted for crack growth, employing an energetic failure criterion in which G I and G II represent the current values of tensile and shear fracture energies, respectively, while  serves as the exponent in the damage law (with  =1 for linear softening)

I G G G G       + =         II IC IIC

(4)

1.

3. Results 3.1. Experimental data

Fig. 3 illustrates the average P m obtained in the experimental study, along with the standard deviations (STDV), plotted against  for the three adhesives. Upon analyzing the data, it becomes evident that there is a consistent trend in strength variation with  for all three adhesives. For  =3.43º, P m for all adhesives were at their highest. Notably, the most significant reduction in P m occurred between  of 3.43º and 10º. When comparing the three adhesives, it is worth highlighting that the AV138 exhibited the best results. Specifically, at  =3.43º, it demonstrated a P m value that was 35.6% and 120.0% higher than that of the 2015 and 7752, respectively. Table 3 displays the average experimental P m , along with the corresponding STDV and coefficients of variation (CoV).

40

30

20

P m [kN]

10

0

0

10

20

30

40

50

α [º]

AV138

2015

7752

Fig. 3. Average experimental P m results and their STDV in relation to  for the three adhesive types.

Table 3. Average P m , and their STDV and CoV, for scarf joints bonded with various adhesive types.

Adhesive

3.43

10

15

20

30

45

 [ o ]

P m [N] STDV [N] CoV [%] P m [N] STDV [N] CoV [%] P m [N] STDV [N] CoV [%]

29700 1500 21903 1600 13500 510.90 5.05 7.30

10648 346.63 7509 772.04 10.28 4677 195.40 3.26

7926 642.49 4858 141.92 3132 286.25 8.11 2.92

5715 310.02 3567 205.56 2378 229.38 5.42 5.76

4480 150.89 2832 101.03 1543 167.86 10.88 3.37 3.57

3325 366.66 11.03 1868 325.56 17.43 1142 63.51

AV138

2015

7752

3.78

4.18

9.14

9.65

5.56