Generalized stress-strain relationship in a wide range of temperatures and draw ratios for high-density polyethylene materials produced by multistage zone-drawing and crystallization of highly deformed melts after extrusion

1994 ◽  
Vol 30 (1) ◽  
pp. 90-94
Author(s):  
Yu. M. Boiko
Keyword(s):  
High Density Polyethylene ◽  
High Density ◽  
Stress Strain ◽  
Wide Range ◽  
Strain Relationship

Stress-strain behavior of high-density polyethylene below the yield point: Effect of unloading rate

2008 ◽  
Vol 50 (5) ◽  
pp. 507-513 ◽  
Author(s):  
Stanislav Abramovich Patlazhan ◽  
K. Hizoum ◽  
Y. Rémond
Keyword(s):  
Yield Point ◽  
High Density Polyethylene ◽  
High Density ◽  
Stress Strain ◽  
Strain Behavior ◽  
Unloading Rate

Dynamic Stress-Strain Relationship of Saturated Clay by Dynamic Triaxial Test

2011 ◽  
Vol 250-253 ◽  
pp. 3183-3186
Author(s):  
Jian Yi Yuan
Keyword(s):  
Triaxial Test ◽  
Dynamic Stress ◽  
Soft Clay ◽  
Confining Pressure ◽  
Dynamic Shear ◽  
Stress Strain ◽  
Dynamic Triaxial Test ◽  
Wide Range ◽  
Strain Relationship ◽  
Relationship Of

Subgrade diseases are exposed more and more serious with raising speed of existing railway in wide range. Fro the complexity of dynamic stress-strain relationship of soil, dynamic triaxial test was used to analyze .the dynamic mechanics behavior under cyclic train load for saturated soft clay in Yangtze Delta region. Compaction coefficient, confining pressure, dynamic shear strsss ratio, inputing stimulus and loading frequence were taken into account in test. The results show that the dynamic stress-strain curves of soil specimen are provided with prominent hysteretic characteristics and area surrounded by hysteretic curves gradually augment and slope of hysteretic curve decreases with the increase of dynamic shear train amplitude. The strong correlation exists between dynamical stress and strain.

An experimental study on foaming of linear low-density polyethylene/high-density polyethylene blends

2016 ◽  
Vol 53 (1) ◽  
pp. 83-105 ◽  
Author(s):  
Peyman Shahi ◽  
Amir Hossein Behravesh ◽  
Ali Haghtalab ◽  
Ghaus Rizvi ◽  
Fatemeh Goharpei
Keyword(s):  
Bulk Density ◽  
High Density Polyethylene ◽  
Cell Structure ◽  
High Density ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Polyethylene Blends ◽  
Wide Range ◽  
Foaming Behavior

In this research work, foaming behavior of selected polyethylene blends was studied in a solid-state batch process, using CO2 as the blowing agent. Special emphasis was paid towards finding a relationship between foamability and thermal and rheological properties of blends. Pure high-density polyethylene, linear low-density polyethylene, and their blends with two weight fraction levels of high-density polyethylene (10 and 25%wt.) were examined. The dry blended batches were mixed using an internal mixer in a molten state, and then the disk-shaped specimens, 1.8 mm in thickness, were produced for foaming purposes. The foaming step was conducted over a wide range of temperatures (120–170℃), and the overall expansion and cellular morphology were evaluated via density measurements and captured SEM micrographs, respectively. Three-dimensional structural images were also captured using a high resolution X-ray micro CT for different foamed samples and were compared. Rheological and DSC tests for the virgin and blends were also performed to seek for a possible correlation with the formability. Based on the results, blended polyethylene foams exhibited remarkable expansion and highly enhanced cell structure compared to pure polymers. Bulk density, as low as 0.33 g/cm3, was obtained for blends, while for the virgin high-density polyethylene  and linear low-density polyethylene, bulk density lower than 0.5 g/cm3 was not attainable. The lowest density was observed at a foaming temperature of 10–20℃ above the melting (peak) temperature obtained via DSC test. Rheological characteristics, including storage modulus and cross-over frequency value, were also found to be the indicators for the materials foaming behavior. Moreover, blends with 25% wt. of high-density polyethylene exhibited the highest expansion values over a wider range of temperature compared with 90% linear low-density polyethylene/10% high-density polyethylene.

Viscoplastic Constitutive Equation of High-Density Polyethylene

2007 ◽  
Vol 340-341 ◽  
pp. 1097-1102 ◽  
Author(s):  
Yukio Sanomura ◽  
Mamoru Mizuno
Keyword(s):  
Constitutive Equation ◽  
Strain Rate ◽  
High Density Polyethylene ◽  
Kinematic Hardening ◽  
Constant Strain Rate ◽  
Strain Curve ◽  
High Density ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Creep Theory

A viscoplastic constitutive equation based on the kinematic hardening creep theory of Malinin-Khadjinsky and the nonlinear kinematic hardening rule of Armstrong-Frederick is formulated to describe the inelastic behavior of high-density polyethylene under various loading. The gentle progress of back stress by the introduction of loading surface in the viscoplastic strain space and smaller material constant under unloading can be expressed. Material constants are identified by various stress-strain curves under compression at constant strain rate and creep curves under compression at constant stress. The viscoplastic model can describe stress-strain curve under compression with change in strain rate and shear stress-strain curve including unloading. The model can qualitatively describe stress-strain curves under compression with changed strain rate including unloading, but it is quantitatively insufficient.

scholarly journals Manufacturing and Characterization of Environmentally Friendly Wood Plastic Composites Using Pinecone as a Filler into a Bio-Based High-Density Polyethylene Matrix

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4462
Author(s):  
Maria del Carmen Morcillo ◽  
Ramón Tejada ◽  
Diego Lascano ◽  
Daniel Garcia-Garcia ◽  
David Garcia-Sanoguera
Keyword(s):  
High Density Polyethylene ◽  
Filler Content ◽  
High Density ◽  
Polyethylene Matrix ◽  
Wood Plastic Composites ◽  
Matrix Interaction ◽  
Plastic Composites ◽  
Wide Range ◽  
Injection Molded

The use of wood plastic composites (WPC) is growing very rapidly in recent years, in addition, the use of plastics of renewable origin is increasingly implemented because it allows to reduce the carbon footprint. In this context, this work reports on the development of composites of bio-based high density polyethylene (BioHDPE) with different contents of pinecone (5, 10, and 30 wt.%). The blends were produced by extrusion and injection-molded processes. With the objective of improving the properties of the materials, a compatibilizer has been used, namely polyethylene grafted with maleic anhydride (PE-g-MA 2 phr). The effect of the compatibilizer in the blend with 5 wt.% has been compared with the same blend without compatibilization. Mechanical, thermal, morphological, colorimetric, and wettability properties have been analyzed for each blend. The results showed that the compatibilizer improved the filler–matrix interaction, increasing the ductile mechanical properties in terms of elongation and tensile strength. Regarding thermal properties, the compatibilizer increased thermal stability and improved the behavior of the materials against moisture. In general, the pinecone materials obtained exhibited reddish-brown colors, allowing their use as wood plastic composites with a wide range of properties depending on the filler content in the blend.

Investigation of the effects of welding variables on the welding defects of the friction stir welded high density polyethylene sheets

2021 ◽  
pp. 009524432110588
Author(s):  
Mustafa Kemal Bilici
Keyword(s):  
Friction Stir Welding ◽  
High Density Polyethylene ◽  
Welding Process ◽  
High Strength ◽  
High Density ◽  
Welding Parameters ◽  
Friction Stir ◽  
Wide Range ◽  
Welding Defects ◽  
Welding Processes

Modern thermoplastic materials are used in an expanding range of engineering applications, such as in the automotive industry, due to their enhanced stress-to-weight ratios, toughness, a very short time of solidification, and a low thermal conductivity. Recently, friction stir welding has started to be used in joining processes in these areas. There are many factors that affect weld performance and weld quality in friction stir welding (FSW). These factors must be compatible with each other. Due to the large number of welding variables in friction stir welding processes, it is very difficult to achieve high strength FSW joints, high welding performance, and control the welding process. Welding variables that form the basis of friction stir welding; machine parameters, tool variables, and material properties are divided into three main groups. Each welding variable has different effects on the weld joint. In this study, friction stir welds were made on high density polyethylene (HDPE) sheets with factors selected from machine parameters and welding tool variables. Although the welding performance, quality, and strength gave good results in some conditions, successful joints could not be realized in some conditions. In particular, welding defects occurring in the combination of HDPE material with FSW were investigated. Welding quality, defects, and performances were examined with macrostructure. In addition, the tensile strength values of some the joints were determined. The main purpose of this study is to determine the welding defects that occur at the joints. The causes of welding defects, prevention methods, and which weld variables caused were investigated. Welding parameters and welding defects caused by welding tools were examined in detail. In addition, the factors causing welding defects were changed in a wide range and the changes in the defects were observed.

Influence of microstructure and morphology on stress-strain behavior of commercial high density polyethylene

2008 ◽  
Vol 110 (1) ◽  
pp. 624-631 ◽  
Author(s):  
Mostafa Zahedi ◽  
Mostafa Ahmadi ◽  
Mehdi Nekoomanesh
Keyword(s):  
High Density Polyethylene ◽  
High Density ◽  
Stress Strain ◽  
Strain Behavior

Dielectric Properties and Relaxation Behavior of High Density Polyethylene (HDPE)

2015 ◽  
Vol 799-800 ◽  
pp. 1319-1324
Author(s):  
F. Benabed ◽  
Tahar Seghier
Keyword(s):  
Dielectric Properties ◽  
Dielectric Response ◽  
High Density Polyethylene ◽  
Chemical Structure ◽  
High Density ◽  
Dielectric Relaxation Spectroscopy ◽  
Dielectric Studies ◽  
Frequency Range ◽  
Wide Range

The method of dielectric spectroscopy is an instrument of choice for the diagnosis of insulation used in high voltage and also to assess the quality of the insulation of HV equipment such as transformers, cables, capacitors, etc...This method allows to estimating the state and the quality of the insulation using the dielectric response of the frequency range. In this article, we have presented results of dielectric studies in high-density polyethylene (HDPE) by means of dielectric relaxation spectroscopy (DRS) in frequency range 10-2 - 106 Hz and temperature between-60 and 60 °C, we will invest this method to measure the dielectric properties and evaluate the performance of this insulator witch has always been chosen as a model polymer material because it is the simplest polymer with respect to its chemical structure and is used in a wide range of applications in daily life.

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