An Experimental Study on the Frictional Property and Long-Term Performance of GT/HDPE Composites

2007 ◽  
Vol 539-543 ◽  
pp. 1043-1046
Author(s):  
Jung Min Seo ◽  
Han Yong Jeon ◽  
Beong Bok Hwang ◽  
Y.H. Lee ◽  
H.S. Koo
Keyword(s):  
Experimental Study ◽  
Creep Deformation ◽  
High Performance ◽  
Reduction Factor ◽  
Frictional Property ◽  
Needle Punching ◽  
Punching Process ◽  
Long Term Performance ◽  
Term Performance

This paper is concerned with the long-term performance of geo-textile (GT) composites in terms of creep deformation and frictional properties. Composites of PVA GT and HDPE GM were made to investigate the advanced properties of long-term performance related to waste landfill applications. The same experiments were also performed for typical polypropylene and polyester GT and compared to PVA GT/HDPE GM composites. The main purpose of this study is to develop high performance GT composites with GM by using PVA GT which is capable of improving frictional property and thus enhances long-term performance of GT composites. In the present experiments, GT composites of PVA GT/HDPE GM, PVA GT of 600, 1000, 1500, 2000g/m2 and HDPE GM were prepared in thermal bonding process. Polyester and polypropylene GT were also made in needle punching process. The creep deformation of GT composites was measured and evaluated in accordance with ASTM D5262. Frictional characteristics of GT composites tested in this study were conducted with compact direct shear apparatus in accordance with ASTM D5321. It was concluded from the present experimental study that friction coefficient of GT composites is relatively large compared with those of polyester and polypropylene non-woven GT as long as the friction media has similar size to the particles of domestic standard earth. In the event that 20% of the maximum tensile strength was added to polypropylene and polyester non-woven geo-textiles, creep deformation reached to 10% or higher, making it even impossible to find reduction factor.

scholarly journals Review on Development and Dental Applications of Polyetheretherketone-Based Biomaterials and Restorations

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 408 ◽  
Author(s):  
Ludan Qin ◽  
Shuo Yao ◽  
Jiaxin Zhao ◽  
Chuanjian Zhou ◽  
Thomas W. Oates ◽  
...  
Keyword(s):  
High Performance ◽  
Dental Resin ◽  
Oral Environment ◽  
Inert Surface ◽  
Oral Implant ◽  
Long Term Performance ◽  
Dental Applications ◽  
Term Performance ◽  
Orthopedic Applications

Polyetheretherketone (PEEK) is an important high-performance thermoplastic. Its excellent strength, stiffness, toughness, fatigue resistance, biocompatibility, chemical stability and radiolucency have made PEEK attractive in dental and orthopedic applications. However, PEEK has an inherently hydrophobic and chemically inert surface, which has restricted its widespread use in clinical applications, especially in bonding with dental resin composites. Cutting edge research on novel methods to improve PEEK applications in dentistry, including oral implant, prosthodontics and orthodontics, is reviewed in this article. In addition, this article also discusses innovative surface modifications of PEEK, which are a focus area of active investigations. Furthermore, this article also discusses the necessary future studies and clinical trials for the use of PEEK in the human oral environment to investigate its feasibility and long-term performance.

scholarly journals Long-Term Settlement of High Concrete-Face Rockfill Dam by Field Monitoring and Numerical Simulation

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xinjie Zhou ◽  
Xinjian Sun ◽  
Junxing Zheng ◽  
Haoyuan Jiang ◽  
Yongye Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Creep Deformation ◽  
Deformation Behavior ◽  
Finite Element Software ◽  
Rockfill Materials ◽  
Stress And Deformation ◽  
Long Term Performance ◽  
Term Performance ◽  
Concrete Face

High concrete-face rockfill dams (CFRDs) with heights of over 100 m have been quickly developed in recent years. The self-weight of rockfill materials causes creep deformation of the dam body. However, the creep analysis method of high CFRDs in finite element software is few, and sometimes, it can also not reflect the long-term performance of high CFRDs well. Therefore, it is necessary to carry out the secondary development in finite element software. This study developed a subroutine that can run in Finite Element Method (FEM) platform ABAQUS to simulate long-term creep deformation behavior of the rockfill materials more accurately. Then, a displacement back-analysis for parameters, based on the Xujixia high CFRD project, is performed by the neural network response surface method (BP-MPGA/MPGA). Remarkable agreements are observed between simulation and field monitoring results. The calibrated FEM model is used to predict stress and deformation behavior of the Xujixia high CFRD after three years of operation period. The result indicates that rockfill creep deformation has a significant impact on stress and deformation of the high CFRD during the operation. This research may predict long-term performance using FEM in the design stage for high CFRDs.

An Investigation of Environmental Reduction Factor for GFRP Bar Used as Concrete Reinforcement in China

2011 ◽  
Vol 413 ◽  
pp. 399-403 ◽  
Author(s):  
Jian Wei Huang
Keyword(s):  
Reduction Factor ◽  
Fiber Reinforced Polymer ◽  
Rc Structures ◽  
Average Temperature ◽  
Reinforced Polymer ◽  
Gfrp Bar ◽  
Temperature Records ◽  
Long Term Performance ◽  
Term Performance

Currently, an environmental reduction factor (ERF) is incorporated in design codes/guidelines of Fiber Reinforced-Polymer (FRP) in reinforced concrete (RC) structures to account for the FRP long-term durability. Due to the lack of real time durability data, justification of the ERF is still necessitated. This paper presents a calibration of ERF for GFRP bar to be used in China on the basis of the prediction of GFRP long-term performance with monthly average temperature records from 32 major cities. Research results show that the ERF values vary from 0.49 to 0.58 at 100% R.H. exposure, while ERFs are greater than 0.70 for all cases being studied when R.H. is below 90%. On the basis of this study, ERF can be recommended as of 0.70 and 0.50 for application with R.H. <90% and moisture saturated exposures, respectively.

Long Term Performance of the SkyTrough Solar Concentrator

2012 ◽  
Author(s):  
David White ◽  
Alison Mason ◽  
Ryan Clark
Keyword(s):  
High Performance ◽  
Additional Data ◽  
Low Cost ◽  
Parabolic Trough ◽  
Optical Efficiency ◽  
Model Predictions ◽  
Electrical Generation ◽  
Long Term Performance ◽  
Term Performance

The SkyTrough is an advanced integrated parabolic trough concentrator designed for high performance and low cost to achieve economic objectives in the market for high grade heat for industrial processes and electrical generation. To achieve low cost, a comprehensive optimization process was carried out for every component based on the choice of low cost silvered polymer film as the reflector. To verify high performance, the optical efficiency of a single module was measured at the National Renewable Energy Lab (NREL), and a demonstration loop was constructed in December, 2009 at the SEGS-II solar power plant in Daggett, CA, USA. This paper compares operating data recorded over eighteen months for the commercial demonstration at the SEGS-II plant with model predictions based on the NREL efficiency measurement. The comparison demonstrates that the SkyTrough system will perform predictably over time. Additional data illustrating the good performance of the collector in wind, and the sustained reflectance of the mirror film, are presented.

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