Determination of the Fracture Toughness Limit of Polypropylene Pipes

A. I. Gerasimov; E. V. Danzanova; G. V. Botvin

doi:10.17804/2410-9908.2018.1.050-057

A. I. Gerasimov, E. V. Danzanova, G. V. Botvin

DETERMINATION OF THE FRACTURE TOUGHNESS LIMIT OF POLYPROPYLENE PIPES

DOI: 10.17804/2410-9908.2018.1.050-057

At present, polypropylene pipes are most widely used in water supply systems. However, there are restrictions on the ambient temperature during their transportation. Thus, transportation, loading and unloading of polypropylene pipes are recommended to be carried out at an ambient temperature of at least minus 10 °C. Transportation is allowed at temperatures down to minus 20 °C, with fixation of pipes and observation of special precautions. This paper presents the results of testing samples of polypropylene pipes for crack resistance at different temperatures. The influence of the surface layer of the outer and inner walls of the pipes on fracture toughness is investigated. The results demonstrate that the removal of the surface layer from the inner wall of the pipe increases the value of the fracture toughness limit.

Keywords: polypropylene, fracture toughness limit, tension, incision, surface layer

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$Fig. 1. Shape and dimensions of samples with an edge crack for fracture toughness testing under axial tension$ $Fig. 2. Photos of the fracture surfaces of polypropylene pipes, the test temperature T = +23 °C: original PP (a); without the inner layer (b); without the outer layer (c)$ $Fig. 3. Photos of the fracture surfaces of polypropylene pipes, the test temperature T = 0 °C: original PP (a); without the inner layer (b); without the outer layer (c)$ $Fig. 4. Photos of the fracture surfaces of polypropylene pipes, the test temperature T = 10 °C: original PP (a); without the inner layer (b); without the outer layer (c)$ $Fig. 5. Photos of the fracture surfaces of polypropylene pipes, the test temperature T = 20 °C: original PP (a); without the inner layer (b); without the outer layer (c)$ $Fig. 6. The effect of the surface layer on the fracture toughness limit at different temperatures$

Article reference

Gerasimov A. I., Danzanova E. V., Botvin G. V. Determination of the Fracture Toughness Limit of Polypropylene Pipes // Diagnostics, Resource and Mechanics of materials and structures. - 2018. - Iss. 1. - P. 50-57. -
DOI: 10.17804/2410-9908.2018.1.050-057. -
URL: http://eng.dream-journal.org/issues/2018-1/2018-1_121.html
(accessed: 12/03/2024).