Machine for testing polymer materials in the three-dimensional stressed state at various temperatures

N. P. Demenchuk; A. Ya. Gol'dman

doi:10.1007/bf01126252

MRV-1M multiposition unit for testing polymer materials in vacuo and in gaseous media

Strength of Materials ◽

10.1007/bf01528768 ◽

1976 ◽

Vol 8 (11) ◽

pp. 1362-1365

Author(s):

K. Sh. Bocharov ◽

Yu. S. Stroilov ◽

V. F. Udovenko ◽

M. V. Zinov'ev ◽

V. I. Momot

Keyword(s):

Polymer Materials ◽

Gaseous Media ◽

Testing Polymer

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PM-14 Three Dimensional Observations and Quantitative Analysis of Functional Polymer Materials

Microscopy ◽

10.1093/jmicro/dfz103 ◽

2019 ◽

Vol 68 (Supplement_1) ◽

pp. i41-i41

Author(s):

Fumiya Uehara ◽

Masayoshi Muraoka ◽

Naoto Kaneko ◽

Yuji Otsuka

Keyword(s):

Quantitative Analysis ◽

Three Dimensional ◽

Polymer Materials ◽

Functional Polymer

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Investigation of strength of shaped elements of the main gas pipeline

JOURNAL OF HYDROCARBON POWER ENGINEERING ◽

10.31471/2311-1399-2019-1(11)-14-21 ◽

2019 ◽

Vol 6 (1) ◽

pp. 14-21

Author(s):

Ya.V. Doroshenko

Keyword(s):

Stressed State ◽

Temperature Difference ◽

Three Dimensional ◽

Gas Pipeline ◽

Cfd Modeling ◽

Dynamic Processes ◽

Internal Cavity ◽

Main Stream ◽

Gas Dynamic ◽

Main Gas Pipeline

The research has been carried out for the purpose of a complex numerical three-dimensional modeling of the stressed state of taps and tees of main gas pipelines taking into account the gas-dynamic processes occurring in these shaped elements and the temperature difference in their walls. A 3D modeling of the elbow with a 90° angle and a reinforcing pad on the main line and the drainage of the passage line of the trunk of the main gas pipeline has been carried out. There has been studied the gas flow with 3D models of shaped elements of the main gas pipeline by means of the CFD modeling. The simulation has been рerformed for the equidistant tees in which the entire flow from the main stream flows into its branch. The mathematical model is based on the solution of the Navier–Stokes equation system, continuity equation, closed by a two-parametric k -e model of the Launder–Sharma turbulence with corresponding initial and boundary conditions. The simulation results are visualized in the ANSYS Fluent R18.2 Academic Postprocessor by constructing the pressure fields on the contours and in the longitudinal and transverse sections of shaped elements. The exact values of pressure at different points of the inner cavity of the shaped elements have been determined, the places of rise and fall of pressure identified. There have been performed the simulation of the temperature difference in the walls of the drainage, the trunk of the main gas pipeline in the module ANSYS Transient Thermal. The results of CFD and temperature modeling were imported into the mechanical module ANSYS Static Structural, where the finite element method was used to simulate the stressed state of the shaped elements of the main gas pipeline, taking into account the gas-dynamic processes occurring in their internal cavity and the temperature difference in the walls. The results of the simulation have been visualized by constructing a three-dimensional color fields of equivalent von Mises stresses in the tee and in the elbow. The places of the maximum equivalent stresses in the wall of the studied shaped elements have been revealed.

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Three-Dimensional Printed PLA and PLA/PHA Dumbbell-Shaped Specimens: Material Defects and Their Impact on Degradation Behavior

Materials ◽

10.3390/ma13082005 ◽

2020 ◽

Vol 13 (8) ◽

pp. 2005 ◽

Cited By ~ 1

Author(s):

Joanna Rydz ◽

Jakub Włodarczyk ◽

Jennifer Gonzalez Ausejo ◽

Marta Musioł ◽

Wanda Sikorska ◽

...

Keyword(s):

Three Dimensional ◽

Hydrolytic Degradation ◽

Processing Parameters ◽

Polymer Materials ◽

Original Research ◽

Polymer Properties ◽

Subsequent Behavior ◽

And Behavior ◽

The Impact ◽

Printing Direction

The use of (bio)degradable polymers, especially in medical applications, requires a proper understanding of their properties and behavior in various environments. Structural elements made of such polymers may be exposed to changing environmental conditions, which may cause defects. That is why it is so important to determine the effect of processing conditions on polymer properties and also their subsequent behavior during degradation. This paper presents original research on a specimen’s damage during 70 days of hydrolytic degradation. During a standard hydrolytic degradation study of polylactide and polylactide/polyhydroxyalkanoate dumbbell-shaped specimens obtained by 3D printing with two different processing build directions, exhibited unexpected shrinkage phenomena in the last degradation series, representing approximately 50% of the length of the specimens irrespective of the printing direction. Therefore, the continuation of previous ex-ante research of advanced polymer materials is presented to identify any possible defects before they arise and to minimize the potential failures of novel polymer products during their use and also during degradation. Studies on the impact of a specific processing method, i.e., processing parameters and conditions, on the properties expressed in molar mass and thermal properties changes of specimens obtained by three-dimensional printing from polyester-based filaments, and in particular on the occurrence of unexpected shrinkage phenomena after post-processing heat treatment, are presented.

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The Effect of Specimen Size on the Determination of Residual Stress in Polymer Pipe Wall

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.627.141 ◽

2014 ◽

Vol 627 ◽

pp. 141-144 ◽

Cited By ~ 1

Author(s):

Jan Poduška ◽

Jaroslav Kučera ◽

Pavel Hutař ◽

Martin Ševčík ◽

J. Křivánek ◽

...

Keyword(s):

Residual Stress ◽

Axial Stress ◽

Three Dimensional ◽

Axial Direction ◽

Polymer Materials ◽

Axial Residual Stress ◽

Axial Dimension ◽

Measured Deformation ◽

Different Dimensions

As a result of the production process, there are axial and tangential residual stresses present in pressure pipes made of polymer materials such as polyethylene or polypropylene. The residual stress magnitude and distribution have a significant influence on the pipe lifetime. In this contribution the results from experiments focused on determining the tangential residual stress distribution in the walls of polypropylene pipes of different dimensions are compared. The experimental method used involves measuring the deformation of ring shaped specimens that were slit in the axial direction. Measured deformation of the ring specimen is a result of the tangential and axial stress superposition. However, the effect of the axial residual stress depends on the specimen axial dimension and tangential residual stress estimated basing on experimental data should be corrected according to axial dimension of the specimen used. The correction suggested in this article is determined based on three-dimensional FEM simulations of the experiment.

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