Determining mechanical properties at the shear of the material of "T" type pressure fire hose based on torsion tests

Abstract

PhD, Associate Professor** O. S h a p o v a l o v PhD** I. S h a s h a Doctor of Technical Sciences** V. D e m i a n y s h y n PhD** A. D e m c h e n k o PhD Department of organization of scientific activity Cherkasy Institute of Fire Safety named after the Heroes of Chernobyl Onoprienka str.,

Determining the dissipative properties of a flexible pipeline’s material at stretching in the transverse direction taking its structural elements into consideration

“…According to [17], the mechanical properties of flexible pipelines could also change when they are twisted at a certain angle. This paper investigated the mechanical properties of the «T» type PFH experimental samples with an inner diameter of 77 mm, which accepted different values of internal hydraulic pressure when changing the angle of twisting.…”

“…The experimental samples investigated in studies [16,17] had no damage before the experiments. These studies did not consider changes in the parameters of the mechanical pro perties of PFH experimental samples that had a certain defect compared to samples without defects.…”

“…Thus, after analyzing the scientific literature [5][6][7][8][9][10][11][12][13][14][15][16][17][18], it was found that most studies address changes in the properties of materials from which flexible pipelines are made, exerted by various influences [5][6][7][8][9][10][11][12][13][14][15][16]18]. In order to diagnose the technical condition of flexible pipelines, the industrial computer tomography method could be applied [15]; however, the complexity of the structure of the material from which they are made limits its application.…”

“…Given the complex structure of flexible pipelines, a series of works [8][9][10][11][12][13][14] investigated changes in the properties of individual layers only, which make up the material for pipelines. A comprehensive estimation of changes in the mechanical properties of the material from which flexible pipelines are made when it is exposed to various influences was reported in works [16,17]. Those studies found that intense fatigue contributes to a change in the properties of the PFH material, the occurrence and propagation of cracks, and, after a certain time, causes their failure.…”

Establishment of the dependence of the strength indicator of the composite material of pressure hoses on the character of single damages

“…In work [13], the mechanical properties of PFH with a diameter of 77 mm were investigated under a static load by stretching prototypes in the transverse direction. In contrast to [12,13], [14] investigated the change in the mechanical properties of PFH with a diameter of 77 mm by rotating the prototypes at a certain angle. When conducting research on rotation [14], certain normalized values of hydraulic pressure were maintained in the inner cavity of the PFH prototypes.…”