PSI - Issue 14

Digendranath Swain et al. / Procedia Structural Integrity 14 (2019) 207–214 Swain et al./ Structural Integrity Procedia 00 (2018) 000–000

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Fig. 1.Photographs showing (a) SCT specimens, (b) PT specimens, (c) zoomed view of the surface crack and (d) the surface crack as seen after failure of the specimen where a-6 mm and b-2mm.

Fig. 2. Photographs showing the DIC and AE setups during (a) SCT specimen and (b) PT specimens tests in the UTM.

2. Experimentation Here, the details of the experiments are provided. Details about DIC and AE principle and procedures can be found in Refs. (Sutton et al. (2009), Scurby (1987)). In this paper, total four specimens have been experimented for correlating AE signals with DIC full-field outputs, 2 SCT and 2 PT specimens (Figs. 1a and 1b). The 6 mm by 2 mm size surface cracks in the SCT specimens were generated in a fatigue test machine from a center notch on the weld. A zoomed view of the surface crack is shown in Fig. 1c. Photograph of a crack depth is shown in Fig. 1d after failure of a typical SCT sample. The DIC random pattern was generated on the SCT specimens after the surface cracks were created on them. In PT specimens random pattern was generated as usual. The details of the test specimens are provided in Table 1. For AE instrumentation the piezo-sensor, pre-amplifier and data acquisition (DAQ) systems were supplied by Physical Acoustics (PAC), USA. Other details of AE instrumentation can be found in Table 2. Similarly, for DIC setup a 3-D DIC system was used as per the details given in Table 2. The experimental setups for tensile testing of SCT and PT specimens are shown in Figs. 2a and 2b, respectively, wherein