PSI - Issue 42

Karlo Seleš et al. / Procedia Structural Integrity 42 (2022) 1721–1727 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

1725

5

Fig. 3. Results of compact tension tests

The cause of the difference in the experimental data of individual sample is the probably due to high brittle behavior. In such case, even the smallest surface or volume defect can influence the final results. According to the acquired material parameters from experimental test, numerical models are created using 2D finite elements with

phase-filed formulation. 3. Numerical validation

The 2D numerical model consist of 42 000 finite elements (Figure 4) in plane stress. Also, two types of formulation are used: the AT2 and TH as stated above. The only difference between the two is the length scale parameter or width of the crack. The TH model doesn’t require such fine mesh and saves computational time. The input material parameters according to experimental test are shown in Table 2.

Table 2. Input parameters of PMMA samples

Model

Standard - AT2

Threshold - TH

Young’s modulus, E [MPa]

3204.3

Poisson’s ratio, ν [-]

0.374

Energy release rate, G c [N/mm]

0.4453

crit  [MPa]

Tensile strength,

59.76

27

3

2 G E  C crit

2 G E  C crit

=

=

0.21

0.04

Length scale parameter, l [mm]

4 2

256