About the Energy Dissipation Coefficient of Thin-Walled Glass-Plastic Pipes with the Initial Reinforcement Asymmetry with Respect to Axis Subjected to Pulsating Internal Hydrostatic Pressure

Abstract

AbstractResults of study of the influence of possible deviation of the symmetric reinforcement relative to the axis (the disorientation of reinforcement) occurred during the material technological processing into a product on the deformation behavior and dissipative properties thin-walled glass-plastic tubular elements subjected to repeated-static internal hydrostatic pressure are discussed. It is stated that under the conditions of repeated-static internal pressure (low-cycle pulsating), in addition to the main cyclic circumferential deformations for symmetrically reinforced pipes (φ = 0°), accompanying the main cyclic longitudinal deformations is arising, and for pipes with the initially broken reinforcement symmetry (φ = 6–8°), accompanying cyclic shear deformations is appearing as well. As is shown, after the stabilization of the deformation process (after 2–3 cycles of loading–unloading), the value of energy dissipation coefficient ψ for glass-plastic pipes with φ = 6–8° turns out to be 20% (and more) greater than the value of energy dissipation coefficient ψ defined for glass-plastic pipes with φ = 0°. The shares of each from the main and accompanying the main deformations into the total energy loss for the glass-plastic pipes with the initially broken reinforcement symmetry (φ = 6–8°) are shown up. Defined that during the process of low-cycle pulsating internal pressure, the amount of energy loss due to the occurrence of cyclic shear and longitudinal deformations accompanying cyclic main circumferential deformations turns out to be 270% and 12% more than the amount of the energy loss arising from the main deformations, respectively. Practical recommendations by the optimal design of thin-walled tubular structural elements made of reinforced plastics operating under conditions of low-cycle pulsating internal pressure are stated.KeywordsThin-walled glass-plastic pipesDisorientation of reinforcementIntensities of shear stresses and the shear strainCoefficient of energy dissipationPulsating internal hydrostatic pressure