PSI - Issue 28

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Vinicius Carrillo Beber et al. / Procedia Structural Integrity 28 (2020) 1950–1962 V.C. Beber and M. Brede / Structural Integrity Procedia 00 (2019) 000–000

1956

3.5. Testing procedures Static tests on adhesive joints were carried under displacement control in Zwick/Roell 100kN testing machine at room temperature with a testing speed of: (a) 0.2 mm/min for the structural adhesive, and (b) 0.55 mm/min for the elastic adhesive. Strain was measured using a video extensometer. Fatigue tests (Figure 5c) were carried out under constant amplitude in accordance with the ISO 12107 (ISO EN, 2012) with force control in a cyclic loading with sinusoidal shape, stress ratio (ratio between minimum and maximum force within one cycle) of R = 0.1, and a frequency of 5 Hz. This frequency was defined to obtain the highest possible frequency (for reduction of testing time) whilst avoiding the risk of thermal heating affecting fatigue results. Stress amplitudes were defined to capture lifetimes from low to high cycle range (10 3 < N < 2.10 6 ). The statistical analysis of the data was carried out based on the ASTM E739 (E08 Committee, 2015) with a 95% confidence interval and a 50% probability of failure.

Figure 4 - Adhesive bonding process for both adhesives

Figure 5 - Adhesively bonded joints: (a) alignment devices, (b) curing at RT, (c) mechanical testing