PSI - Issue 52

Chen Zhou et al. / Procedia Structural Integrity 52 (2024) 234–241 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

236

3

of Zhou et al. (2023).

The ERR can be expressed as ( ) 2 2 2 11 1 4 H   + 

  

G

(3)

=

  +

 

y

x

8

H x H

11

22

where c c and c f are stiffness parameters of the core and face sheet, respectively.

Fig. 1. The MCSDE method is presented schematically. (Zhou et al. 2023)

3. Parametric fracture analysis 3.1. Effect of different moment ratios under static loading

To verify the accuracy of the proposed numerical method, we used DCB-UBM specimens with the same load values and geometric properties as Burlayenko et al.’s work (2019). The geometric model of the specimen is shown in Fig. 2 (a), the length L is set to 270 mm, the thickness of both upper and lower face sheets is set to 2.4 mm, and the thickness of the core is set to 30 mm. The finite element model is shown in Fig. 2 (c). The material properties are shown in Table 1. A constant moment load is applied in two arms of the specimen and the specific values of the moment load are shown in Table 2. The analytical solution is calculated by Eq. (4) (Kardomateas et al. 2013). ( ) ( 1) ( 1) 2 3 2 2 2 1 2 1 1 2 3 2 2 2 1 1 1 2 12 ( ) ( ) f f zx xz f d s s f f f s s d s s M h P M M P P G E H H H E h EA D D EA D         −       = + + + +           (4) where D d and D s are bending rigidity per unit width for debonded part and substrate part, respectively. 3 1 1 12 f d f h D E = (5) 2 3 3 2 2 2 2 2 2 12 12 2 2 f f c c s c c c s f f f s h h h h D E E h e E E h e   = + + +  + −    (6) H 1 , H 2 and H 3 can be expressed as ( ) ( ) ( 2) ( 2) 1 2 2 1 1 2 2 c c f f zx xz zx xz c c f f H E h E h     − − = + (7)