PSI - Issue 41

M.R.M. Aliha et al. / Procedia Structural Integrity 41 (2022) 87–93 Aliha et al. / Structural Integrity Procedia 00 (2022) 000 – 000

90

4

Fig. 2. Four distinct permutations of the Bi-ASB specimen based on the adherent type considered for the Finite Element analyses. Table. 1. Mechanical properties of the adhesive and adherents used to create the Bi-ASB specimen [6] Material Properties Elastic modulus, E (GPa) Poisson’s ratio, ν Fracture toughness, K Ic (MPa √m) Alumina 300 0.21 3.5 Aluminum alloy 70 0.33 29 Epoxy adhesive 2.84 0.35 1.5 The stress intensity factors K I and K II for the Bi-ASB specimen are functions of the crack length and the positions of the bottom span supports described by S ′ and S. These two fracture parameters can be expressed as below

equation for the Bi-ASB specimen: = 3 ′ 2 ( + ′ ) √ ; = .

(1)

where F is the applied load, t is thickness of the adherents, and Y i is the geometry factors of modes I and II. Several finite element (FE) models of the Bi-ASB specimen were created to calculate the mode I and mode II geometry factors (i.e. Y I and Y II ) by using the ABAQUS commercial code.

3. Finite Element Analyses Table 2 shows the overall dimensions of the Bi-ASB specimen utilized in the Finite Element (FE) modeling of this research. Fig. 3 illustrates the FE model of the Bi-ASB specimen, built-in ABAQUS commercial code based on the J-contour integral method. This model is composed of 7600 CPE8 (i.e. 8-node biquadratic plane strain quadrilateral) elements. The produced FE models were subjected to a vertical load of F = 100 N, and the mechanical properties of each part listed in Table 1 were assigned to the models. Very fine and singular type fine elements were employed to simulate the crack tip region and construct the crack tip stress/strain singularity [8]. Also finer meshes were used at the interface between adhesive and adherent due to high-stress concentration at this region, as shown in Fig. 3.

S ′ (mm) In the range of 37.8 to 2.16.

Table. 2. Overall dimensions of the Bi-ASB specimen utilized in the finite element modeling.

Parameter

L (mm)

W (mm)

t (mm)

d (mm)

a (mm)

S (mm)

value

54

15

5

0.4

7.5

37.8