PSI - Issue 32

Irina A. Bannikova et al. / Procedia Structural Integrity 32 (2021) 10–16 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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The samples were 13.78 mm in height and from 11.89 to 12.17 mm in diameter; the density of fused quartz was ~ 2150 kg/m 3 . Images of the experimental setup and the specimen after loading (see Fig. 2). To preserve the fragments, quartz specimens were wrapped in several layers of adhesive tape. Tests of cylindrical quartz samples were carried out on an electromechanical universal testing machine Shimadzu AGX-Plus. The cylindrical specimen was placed in the center of the platform between the tungsten carbide pads in order to exclude deformation of the plate-traverses of the loading machine. Fractoluminescence was registered by two methods. The first used the joint operation of a photomultiplier and a 4-channel Tektronix DPO 7254 Digital Phosphor Oscilloscope FD. In the second, a high speed Photron FASTCAM SA-Z 2100K video camera was used, which simultaneously filmed sample destruction and fractoluminescence. The loading rate was 2 mm/s.

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Fig. 2. (a) photograph of an experiment for uniaxial quasi-static compression: 1 – a electromechanical universal testing machine Shimadzu AGX Plus, 2 – a sample, 3 – a displacement, 4 – screen, 5 – high speed camera Photron FASTCAM SA- Z 2100K (frequency 6×10 4 frames/s), 6 – lighting; (b) view of specimen No. 6 after loading. 3. Results and discussion The Fig. 3 shows the curves of the dependence of the loading force F on the displacement a . Red curves ( 1 , 3 , 5 , 6 , 7 ) for samples wrapped with tape, blue curves ( 9 , 10 , 11 ) without tape. For curve 2 of the sample (in scotch tape), a substrate of copper plates was used, for others, a substrate was made of tungsten carbide.

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Fig. 3. Loading curves for all samples.