FE simulation of rate-dependent behaviours of polymer geosynthetic reinforcements for an estimation of mobilized tensile force in a reinforced soil

2016 ◽  
Vol 80 ◽  
pp. 49-58 ◽  
Author(s):  
Wenzheng Shi ◽  
Fangle Peng ◽  
Warat Kongkitkul
Keyword(s):  
Fe Simulation ◽  
Tensile Force ◽  
Reinforced Soil ◽  
Rate Dependent

FEM Analysis on Tensile Force of Geosynthetic Reinforcement Arranged in GRS-RW Considering Variable Loading Rate

2012 ◽  
Vol 188 ◽  
pp. 60-65
Author(s):  
Fu Lin Li ◽  
Fang Le Peng
Keyword(s):  
Finite Element ◽  
Loading Rate ◽  
Retaining Wall ◽  
Tensile Force ◽  
Fem Analysis ◽  
Reinforced Soil ◽  
Geosynthetic Reinforcement ◽  
Geosynthetic Reinforced Soil ◽  
Rate Dependent ◽  
Dependent Behavior

The combined effects of the rate-dependent behavior of both the backfill soil and the geosynthetic reinforcement have been investigated, which should be attributed to the viscous property of material. A nonlinear finite element method (FEM) analysis procedure based on the Dynamic Relaxation method was developed for the geosynthetic-reinforced soil retaining wall (GRS-RW). In the numerical analysis, both the viscous properties of the backfill and the reinforcement were considered through the unified nonlinear three-component elastic-viscoplastic model. The FEM procedure was validated against a physical model test on geosynthetic-reinforced soil retaining wall with granular backfill. Extensive finite-element analyses were carried out to investigate the tensile force distributions in geosynthetic reinforcement of geosynthetic-reinforced soil retaining wall under the change of loading rate. It is found from the analyses that the presented FEM can well simulate the rate-dependent behavior of geosynthetic-reinforced soil retaining wall and the tensile force of geosynthetic reinforcement arranged in retaining wall.

scholarly journals Hydrodynamic Shear Effects on Grafted and Non-Grafted Collapsed Polymers

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 926 ◽  
Author(s):  
Richard Schwarzl ◽  
Roland Netz
Keyword(s):  
Shear Rate ◽  
Brownian Dynamics ◽  
Tensile Force ◽  
Grafted Polymers ◽  
Critical Shear Rate ◽  
Rate Dependent ◽  
Coil Transition ◽  
Hydrodynamic Shear ◽  
Linear Shear ◽  
Dynamics Simulations

We study collapsed homo-polymeric molecules under linear shear flow conditions using hydrodynamic Brownian dynamics simulations. Tensile force profiles and the shear-rate-dependent globular-coil transition for grafted and non-grafted chains are investigated to shine light on the different unfolding mechanisms. The scaling of the critical shear rate, at which the globular-coil transition takes place, with the monomer number is inverse for the grafted and non-grafted scenarios. This implicates that for the grafted scenario, larger chains have a decreased critical shear rate, while for the non-grafted scenario higher shear rates are needed in order to unfold larger chains. Protrusions govern the unfolding transition of non-grafted polymers, while for grafted polymers, the maximal tension appears at the grafted end.

Effects of Temperature and Forming Speed on Square Cup Drawability of AZ31 Magnesium Alloy Sheet

2013 ◽  
Vol 871 ◽  
pp. 211-214
Author(s):  
Takashi Katahira ◽  
Tetsuo Naka ◽  
Yasuhide Nakayama ◽  
Ryutaro Hino ◽  
Fusahito Yoshida
Keyword(s):  
Room Temperature ◽  
Fe Simulation ◽  
Alloy Sheet ◽  
Rate Dependent ◽  
Az31 Magnesium Alloy Sheet ◽  
Az31 Sheet ◽  
Effects Of Temperature ◽  
High Temperature Tensile ◽  
Cup Drawing ◽  
High Temperature Tensile Properties

Square cup drawing experiments were performed on an AZ31 sheet at various temperatures (T) ranging from room temperature to 200°C with three different punch travel speeds (V) of 3, 30 and 300mm/min. From the experiment, the highest drawability was observed either at T=175°C with V= 30mm/min or at T=200°C with V= 300mm/min. The effects of temperature and forming speed on the formability were discussed by comparing the result of drawing experiment with the high temperature tensile properties of the material. The forming limits were well predicted by FE simulation using a temperature and rate dependent constitutive model.

FEM Simulation of Earth Pressure on Geosynthetic-Reinforced Soil Retaining Wall under Variable Rate Loading

2012 ◽  
Vol 594-597 ◽  
pp. 266-269
Author(s):  
Fu Lin Li ◽  
Fang Le Peng
Keyword(s):  
Finite Element ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Reinforced Soil ◽  
Physical Model Test ◽  
Variable Rate ◽  
Geosynthetic Reinforced Soil ◽  
Rate Dependent ◽  
The Earth ◽  
Dependent Behavior

On the basis of the Dynamic Relaxation method, a nonlinear finite element method (FEM) analysis procedure was developed for the geosynthetic-reinforced soil retaining wall. The FEM procedure technique incorporated the unified three-component elasto-viscoplastic constitutive model which can consider the rate-dependent behavior of both the backfill soil and the geosynthitic reinforcement. A simulation was performed on a physical model test on geosynthetic-reinforced soil retaining wall to validate the presented FEM. Extensive finite-element analyses were carried out to investigate the earth pressure distributions from the back of retaining wall under variable rate loading. It is shown that this FEM can well simulate the rate-dependent behavior and the earth pressure of geosynthetic-reinforced soil retaining wall.

scholarly journals Wall Displacement and Tensile Force Distribution on Geosynthetics in Reinforced Soil Wall.

2000 ◽  
pp. 21-33
Author(s):  
Jun NISHIMURA ◽  
Masayuki HYODO ◽  
Yukio NAKATA ◽  
Hidekazu MURATA ◽  
Takeharu KONAMI ◽  
...  
Keyword(s):  
Tensile Force ◽  
Reinforced Soil ◽  
Force Distribution ◽  
Wall Displacement ◽  
Reinforced Soil Wall

Stress Redistributions Due to Creep Behavior and Seismic Response of Model Geosynthetic Reinforced Soil Retaining Structures

2013 ◽  
Vol 311 ◽  
pp. 550-555
Author(s):  
Sao Jeng Chao ◽  
Howard Hwang ◽  
An Cheng
Keyword(s):  
Seismic Response ◽  
Creep Behavior ◽  
Tensile Force ◽  
Reinforced Soil ◽  
Clayey Soils ◽  
Retaining Structures ◽  
Geosynthetic Reinforced Soil ◽  
Tensile Forces ◽  
Significant Research ◽  
Simple Factor

Geosynthetic reinforced soil retaining structures (GRSRS) become popular in the recent decades because of the advantages of easy construction, consuming waste soil in the construction site, supreme seismic resistance ability, etc. For the reason that clayey soils cover a wide area in Taiwan, clayey soils are often used as the backfilled materials for the GRSRS. Besides, during the 921 Chi-Chi Earthquake, a few GRSRS were destroyed. Consequently, the dynamic analysis of GRSRS turns out to be another significant research topic. In this paper, we investigate the creep behavior and the seismic response of model GRSRS by using finite element simulation. The predicted results indicated that the tensile stress of the reinforcement is increasing with time as well as under earthquakes. The tendency of the incremental tensile forces due to the clayey backfill soil creep behavior is significant in the initial stage but slows down with time goes on. Observing the predicted results of the GRSRS under different earthquake scales, it is found that the acceleration variations and the tensile force distribution of the reinforcement layers can not be evaluated with a simple factor.

scholarly journals Stability of Extended Earth Berm for High Landfill

2020 ◽  
Vol 10 (18) ◽  
pp. 6281
Author(s):  
Haoran Jiang ◽  
Xiaowen Zhou ◽  
Ziwei Xiao
Keyword(s):  
Tensile Force ◽  
Reinforced Soil ◽  
Steep Slope ◽  
Site Condition ◽  
Promising Alternative ◽  
Geosynthetic Reinforced Soil ◽  
Pile Arrangement ◽  
Leachate Level ◽  
A Site ◽  
Better Than

This study presents a stability analysis of an extended berm reinforced by geotextiles, with a steep slope of 1V:1.1H (vertical: horizontal). Finite element (FE) analyses were carried out to explore the failure mechanism and factor of safety (FOS) of the berm, on which the effect of the strength of geotextiles, leachate level, and anti-slide pile arrangement located at the toe of the berm were considered. It was found that: (1) failure surfaces developed along the interface between the new and the existing berms; (2) the FOS decreased as the leachate increased, and an FOS value of 1.42 could be obtained if the leachate level was controlled at a height of 20 m; (3) the tensile force of geotextiles was far lower than the available strength, which suggested that the geotextile had enough of a safety reserve; and (4) one row of longer piles at the toe of the berm performed better than two rows of shorter piles if the total length of piles was the same. The design and analysis of this project can be used as a reference for landfill expansion. Especially for a site condition with limited space, a geosynthetic-reinforced soil (GRS) berm is a safe, reliable and promising alternative.

scholarly journals Inclined model experiment and discrete element method simulation of reinforced soil wall with leakage of backfill material

2019 ◽  
Vol 92 ◽  
pp. 17005
Author(s):  
Takehiko Nitta ◽  
Hiroaki Miyatake ◽  
Toshikazu Sawamatsu ◽  
Tomohiro Fujita ◽  
Noboru Sato ◽  
...  
Keyword(s):  
Discrete Element Method ◽  
Tensile Force ◽  
Discrete Element ◽  
Reinforced Soil ◽  
Contact Forces ◽  
Normal Contact ◽  
Model Experiments ◽  
Backfill Material ◽  
Reinforced Soil Wall ◽  
Element Method

In this study, a series of inclined model experiments were conducted to investigate the behaviour of reinforced soil walls with leakage of backfill material. The experimental results were simulated by discrete element method (DEM). From the results of the inclined model experiments, it was confirmed that the tensile force in the reinforcement near the wall facing decreased due to the leakage of the backfill material, while decreasing the horizontal resistance of the reinforced soil wall remarkably. The leakage behaviour observed in the experiment was simulated using DEM. From the results of the DEM simulation, the calculated displacement pattern was found to be roughly similar to that obtained in the experiment. During leakage of the backfill material, an area without normal contact forces was generated at the lower end and this area developed toward the upper side. Such a change in normal contact forces affects the behaviour of a geogrid, in particular the disappearance of normal contact forces weakens the interlocking between the geogrid and the soil. This observation agrees with the experimental finding that the strain of the geogrid decreased in the area near the back of the wall facing.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

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