Bending strength and fracture of glass materials under the different loading conditions

Yurii Rodichev, Alexandr Netychuk, Vladimir Bodunov, Yury Yevplov, Vladimir Maslov

Shapes and sizes of surface micro-cracks have the significant influence on glass component strength and durability as well as on the component fracture behavior under mechanical loading. The results of experimental study of bending strength and specific surface micro-crack growth at the flat glass components under short time and durable loading are discussed. Specimens with typical micro-cracks for usual glass surface state and with artificial micro-cracks as well as integrated method of bending test and fractography of fracture surface of specimens were used.

The experimental correlation between geometric parameters, orientation and sizes of initial microcracks placed at the focus of mirror part of specimen fracture surface and crack resistance parameters of glass under the bending was established at the different loading conditions. Specific subcritical surface micro-crack growth under static and low-velocity dynamic loading was studied. The results were obtained in our tests taking into account edge and distant from edge breakage origins (edge and central micro-cracks).

The experimental fracture toughness data received at the testing of the specimens with natural and artificial micro-cracks were different as a result of influence of complex shape and orientation of surface micro-cracks at the real glass component after their mechanical processing and exploitive damaging. That is why the design calculations based on linear fracture mechanics must be supplemented with experimental data received at the testing of specimens made of glass which will be used at the structure working. It was shown that surface quality of initial flat glass increasing as well as the improvement of different processing technologies for glass components production taking into account the surface unsoundness of glass are the important instruments for product workability guaranteeing. This method of experimental fracture analysis may be used at the expert examination of building and automotive glass fracture as well as for glass machinery and technology development.

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The Authors

	Dr. Yurii Rodichev Dr. Head of the Department G.S.Pisarenko Institute for Problems of Strength of NASU Scientist and specialist on glass and ceramics constructional strength. Design and testing of glass and ceramics structures for different spheres of technics. Dr. Yurii Rodichev is the Head of the ... Read more
	Dr. Volodymir Maslov Senior researcher/Dr. V.E. Lashkarjakov Institute of Semoconductor Physics of NASU After graduation from the Moscow Engineering Physics Institute (MEPhI, State University) in 1969, Mr. Maslov received Ph.D. degree in 1973. Since 1974 to 2000 he worked at the enterprises of optical i... Read more