PSI - Issue 42

Michael Brünig et al. / Procedia Structural Integrity 42 (2022) 1137–1144

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M. Bru¨nig et al. / Structural Integrity Procedia 00 (2019) 000–000

(b)

(a)

Fig. 1. (a) Biaxial test machine, (b) Lighting system and camera equipment

(a)

A-A (c)

(b)

R2

R3 A A

4

2

5

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F 1 u 1.1

15.0

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F 2 [kN]

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F 2

P 1/+1 NP 1/+1 F 1 [kN]

u 2.1

F 2

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F 1 u 1.2

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0.0 5.0 10.0 15.0

Fig. 2. H-specimen : (a) photo, (b), (c) details of the geometry in notched parts (all dimensions in mm), (d) forces and displacements, (e) loading paths

rate equations (2) and (6) is realized by the inelastic predictor–elastic corrector method Bru¨nig (2003b). In the simulations eight-node-elements of type Solid185 have been used to compute strains and stresses in the specimen.

3.3. Results of biaxial experiments and corresponding numerical simulations

Load-displacement curves related to axis 1 (a1) and axis 2 (a2), respectively, based on experiments (Exp) and corresponding numerical simulations (Sim) are shown in Fig. 3. In particular, for the proportional (Fig. 3(a)) and the non-proportional case (Fig. 3(b)) good agreement between experiments (Exp) and the corresponding numerical simulations (Sim) can be seen. Figure 4 shows comparison of the first principal strain fields in the notched region of the H-specimen. For example, at the end of the proportional loading path (P 1 /+ 1 end) high principal strains localized in a vertical band up to 106% have been monitored by the experiment (Exp). This strain distribution is also predicted