PSI - Issue 51

Zhihua Xiong et al. / Procedia Structural Integrity 51 (2023) 179–184 Z. Xiong et al. / Structural Integrity Procedia 00 (2022) 000–000

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Under static load, the stress distribution of the CL-shaped dowel is shown in Fig. 6(a). Therefore, a half elliptical crack is inserted into the stress concentration region of CL-shaped dowel. Crack propagation was calculated using the XFEM method. The definition of the XFEM method does not need to specify Assign Seam (special-crack), but rather a separate crack modeling. XFEM method needs to specify relevant parameters in the field output, otherwise, the crack will not expand. For this model, the cracking path of the obtained crack is shown in Fig. 6(b):

a

b

Fig. 6. (a) stress distribution of dowels in T-shaped beams; (b) path of crack propagation of dowels.

The rule of stress intensity factor (K Ⅰ ) of CL-shaped dowel with crack length ‘a’ was discussed. In the XFEM method, the energy method was selected as the crack initiation standard. The results are shown in Fig. 7.

3500

3000

stress intensity factor

2500

1000 stress intensity factor ( MPa*mm ½ ) 1500 2000

500

0

0

5

10

15

20

25

30

crack length a (mm)

Fig. 7. Result of bending and shearing tests –SIF vs crack length.

As expected, the calculated SIF is in an appropriate range, which proves the feasibility of this method. As there is no specific experimental data so far, these results can only be used as a qualitative estimate. 4. Pull-out model The analysis of the pull-out model is similar as the previous model and the loading scheme of the specimen is shown in Fig. 8.

Fig. 8. Pull-out model.