PSI - Issue 32

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

11

2

example, drilling oil and gas wells) or that threaten life (meteorites, etc.). The paper presents an experimental study of the fragmentation of cylindrical fused silica samples under conditions of quasi-static compression in order to establish the laws of the fragments mass (size) distribution with joint registration of fractoluminescence in order to establish a connection between self-similar deformation and fracture laws with multiscale mechanisms of structural relaxation caused by the behavior of mesoscopic defects Naimark and et. al. (2017).

Nomenclature a

displacement of the loading sensor in the installation Shimadzu

F

loading force in the installation Shimadzu

m N

mass of fragments

fragments number of one mass is greater than some given

N time time intervals the number between pulses in the fractoluminescence signal is greater than some specified t imp time interval between pulses in a fractoluminescence signal

2. Material and methods Fused quartz (SiO 2 ) was selected for testing because of its piezoelectric properties and intense fractoluminescence by Kats andSimanovich (1974). Quartz samples were provided by LLC "MegaQuartz", in the city of Gus-Khrustalny, Russia. In order to obtain parallel contact surfaces, the following procedure was proposed. Specimens were placed inside a steel ring then the rest was filled with a mixture of epoxy resin and sand (see Fig. 1). After the mixture with the samples has hardened, level the bases on both sides on a milling machine with magnetic grip. The resulting “disc” was then polished on both sides by Struers on SiC -paper with p500 and p1000 abrasive paper. The resulting bases were etched for 5 seconds in hydrofluoric acid to heal microcracks, then thoroughly washed with water. After that, the disk with the samples was placed into the oven with temperature of 150 °C for 1 hour. After the epoxy mixture had softened, the cylinders were easily released and thoroughly cleaned of the mixture.

a

b

3

1

4

2

5

Fig. 1. Preparation of fused silica samples, SiO 2 . (a): 1 – steel hoop, 2 – quartz samples fixed in a clamp, 3 – ingredients for preparing epoxy resin, 4 – sand of one fraction, 5 – disc with samples in a mixture; (b) Polisher Struers.