Tenth Canadian Geotechnical Colloquium: Recent developments in consolidation of natural clays

1988 ◽  
Vol 25 (1) ◽  
pp. 85-107 ◽  
Author(s):  
Serge Leroueil
Keyword(s):  
Global Analysis ◽  
Strain Curve ◽  
The Self ◽  
Permeability Measurement ◽  
Stress Strain Curve ◽  
Consolidation Process ◽  
Recent Developments ◽  
Natural Clays ◽  
Excellent Tool

A global analysis of the consolidation of natural clays is realized considering the consolidation process to be a combination of the effects of compressibility and of permeability. The compressibility or stress–strain curve followed is strongly influenced, both in the laboratory and in situ, by the strain rate. The self-boring permeameter appears to be an excellent tool for permeability measurement; however, in homogeneous clays direct measurement in the laboratory also gives representive results. The coefficients of consolidation determined graphically strongly underestimate the in situ coefficient. The consolidation must thus be analysed by considering compressibility and permeability parameters measured separately. Key words: consolidation, clay, compressibility, permeability.

Mechanical Behavior of Ion-Irradiated Fe-Cr alloys Investigated by Spherical Indentation

2012 ◽  
Vol 1424 ◽  
Author(s):  
Christopher D. Hardie ◽  
Steve G. Roberts ◽  
Andrew J. Bushby
Keyword(s):  
Plastic Zone ◽  
Strain Softening ◽  
Strain Curve ◽  
Spherical Indentation ◽  
Stress Strain Curve ◽  
Damage Layer ◽  
Dual Beam ◽  
Tip Radius ◽  
Fe Ions

ABSTRACTFe12%Cr was irradiated with 2MeV and 0.5MeV Fe+ ions at 320°C, to create a layer with a mean level of displacement damage of 6.18dpa to a depth of ∼800nm. Spherical indentation, with a nominal tip radius of 10μm, was used to investigate the mechanical properties of the damage layer. Indents produced with loads of 2mN, 3mN, 5mN and 10mN were cross-sectioned and fabricated into TEM foils using an in situ lift-out technique in a dual beam FIB-SEM microscope. The extent of the plastic zone beneath the indent was observed in the TEM for each indentation. The indentation results were analysed so as to give an indentation stress-strain curve, in which strain softening was found to occur beyond the yield point. At loads up to 3mN the plastic zone remained entirely within the damage layer, implying strain-softening of the damaged material. At higher indentation loads the plastic zone was observed to extend into the softer un-irradiated substrate, giving rise to a further fall in flow stress with increasing strain.

X-Ray Diffraction Study of Shape Memory in Uranium-Niobium Alloys

1982 ◽  
Vol 26 ◽  
pp. 307-312 ◽  
Author(s):  
D. A. Carpenter ◽  
R. A. Vandermeer
Keyword(s):  
Shape Memory ◽  
Diffraction Study ◽  
Strain Curve ◽  
X Ray Diffraction ◽  
Stress Strain Curve ◽  
Niobium Alloys ◽  
X Ray ◽  
Scan Time ◽  
Diffraction Patterns

An x-ray diffraction study of the reversible deformation inodes associated with the shape memory effect has been carried out on a series of uranium-niobium alloys near the monotectoid composition (6.2 wt. % Nb). Diffraction patterns were measured as a function of strain, in situ, while the specimens were under stress as part of an attempt to explain the “easy-flow”, low-strain plateau in the stress-strain curve. The alloys, consisting of highly twinned, metastable α” (monoclinic) and γ° (tetragonal) phases derived from the high-temperature BCC γ phase, produced broad, overlapping diffraction lines difficult to analyze by conventional techniques. One solution to this problem was to use a segmented step-scan technique so as to apportion the scan time to concentrate on the most difficult regions. This paper discusses data obtained from an α” alloy and a dual-phase α” + γ° alloy.

In-Situ Observation of Deformation Associated with R-Phase in NiTi Shape Memory Alloy

1995 ◽  
Vol 404 ◽  
Author(s):  
Y. Gao ◽  
Y. Q. Liu ◽  
K. H. Wu
Keyword(s):  
Martensite Transformation ◽  
Room Temperature ◽  
Strain Curve ◽  
Deformation Mode ◽  
Niti Shape Memory Alloy ◽  
In Situ Observation ◽  
Stress Strain Curve ◽  
Second Stage ◽  
Transmission Electron

AbstractAn in-situ straining experiment was performed in a transmission electron microscope (TEM) on the polycrystalline Ti49Ni51 alloy with full R-phase at room temperature. The reorientation of Rphase variants to a single, favorable one was observed under small stress at the beginning of straining, corresponding to the deformation mode of the first yielding stage. During further straining, the observation showed that the reoriented R-phase undergoes a stress-induced martensite transformation, and this dynamic process was considered to contribute to the second stage deformation in the R-phase stress-strain curve. The orientation relationship between the R-phase and stress-induced martensite has been determined and the internal (001)M twins were found in the stressinduced martensite plates.

Recent Developments in the Asymmetric Detrifluoroacetylative Reactions of in situ Generated Mono-Fluorinated Enolates

2020 ◽  
Vol 24 (18) ◽  
pp. 2181-2191
Author(s):  
Li Wang ◽  
Ziyi Li ◽  
Jiang Liu ◽  
Jianlin Han ◽  
Hiroki Moriwaki ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Bond Cleavage ◽  
Synthetic Methodology ◽  
Research Topics ◽  
Synthetic Organic Chemistry ◽  
Nucleophilic Reactions ◽  
F Center ◽  
Recent Developments

The development of an efficient and mild synthetic methodology for the construction of bioactive fluorine-containing molecules represents one of the hot research topics in general synthetic organic chemistry. In this review, some recent progresses achieved in the development of detrifluoroacetylatively generated mono-fluorinated enolates via CC bond cleavage and their asymmetric nucleophilic reactions for assembly of chiral quaternary C-F center containing compounds.

scholarly journals A Review on LDH-Smart Functionalization of Anodic Films of Mg Alloys

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 536
Author(s):  
Mosab Kaseem ◽  
Karna Ramachandraiah ◽  
Shakhawat Hossain ◽  
Burak Dikici
Keyword(s):  
Industrial Applications ◽  
Mg Alloys ◽  
Anodic Films ◽  
Electrolytic Oxidation ◽  
Recent Developments ◽  
Plasma Electrolytic ◽  
Co Precipitation ◽  
Corrosive Environments ◽  
Double Hydroxide

This review presents an overview of the recent developments in the synthesis of layered double hydroxide (LDH) on the anodized films of Mg alloys prepared by either conventional anodizing or plasma electrolytic oxidation (PEO) and the applications of the formed composite ceramics as smart chloride traps in corrosive environments. In this work, the main fabrication approaches including co-precipitation, in situ hydrothermal, and an anion exchange reaction are outlined. The unique structure of LDH nanocontainers enables them to intercalate several corrosion inhibitors and release them when required under the action of corrosion-relevant triggers. The influences of different variables, such as type of cations, the concentration of salts, pH, and temperature, immersion time during the formation of LDH/anodic film composites, on the electrochemical response are also highlighted. The correlation between the dissolution rate of PEO coating and the growth rate of the LDH film was discussed. The challenges and future development strategies of LDH/anodic films are also highlighted in terms of industrial applications of these materials.

A modified version of MATLAB application window for predicting the weld bead profile and stress–strain plot of AA5052 CMT weldment using ER4043

SIMULATION ◽  
2021 ◽  
pp. 003754972110315
Author(s):  
B Girinath ◽  
N Siva Shanmugam
Keyword(s):  
Strain Curve ◽  
Weld Bead ◽  
Welding Parameters ◽  
Bead Geometry ◽  
Hybrid Technique ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Weld Bead Geometry ◽  
Inference System ◽  
Engineering Stress

The present study deals with the extended version of our previous research work. In this article, for predicting the entire weld bead geometry and engineering stress–strain curve of the cold metal transfer (CMT) weldment, a MATLAB based application window (second version) is developed with certain modifications. In the first version, for predicting the entire weld bead geometry, apart from weld bead characteristics, x and y coordinates (24 from each) of the extracted points are considered. Finally, in the first version, 53 output values (five for weld bead characteristics and 48 for x and y coordinates) are predicted using both multiple regression analysis (MRA) and adaptive neuro fuzzy inference system (ANFIS) technique to get an idea related to the complete weld bead geometry without performing the actual welding process. The obtained weld bead shapes using both the techniques are compared with the experimentally obtained bead shapes. Based on the results obtained from the first version and the knowledge acquired from literature, the complete shape of weld bead obtained using ANFIS is in good agreement with the experimentally obtained weld bead shape. This motivated us to adopt a hybrid technique known as ANFIS (combined artificial neural network and fuzzy features) alone in this paper for predicting the weld bead shape and engineering stress–strain curve of the welded joint. In the present study, an attempt is made to evaluate the accuracy of the prediction when the number of trials is reduced to half and increasing the number of data points from the macrograph to twice. Complete weld bead geometry and the engineering stress–strain curves were predicted against the input welding parameters (welding current and welding speed), fed by the user in the MATLAB application window. Finally, the entire weld bead geometries were predicted by both the first and the second version are compared and validated with the experimentally obtained weld bead shapes. The similar procedure was followed for predicting the engineering stress–strain curve to compare with experimental outcomes.

scholarly journals Review: Filament Winding and Automated Fiber Placement with In Situ Consolidation for Fiber Reinforced Thermoplastic Polymer Composites

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1951
Author(s):  
Yi Di Boon ◽  
Sunil Chandrakant Joshi ◽  
Somen Kumar Bhudolia
Keyword(s):  
Processing Parameters ◽  
Filament Winding ◽  
Reference Points ◽  
Thermoplastic Composites ◽  
Manufacturing Processes ◽  
Fiber Reinforced ◽  
Consolidation Process ◽  
Fiber Placement ◽  
Automated Fiber Placement

Fiber reinforced thermoplastic composites are gaining popularity in many industries due to their short consolidation cycles, among other advantages over thermoset-based composites. Computer aided manufacturing processes, such as filament winding and automated fiber placement, have been used conventionally for thermoset-based composites. The automated processes can be adapted to include in situ consolidation for the fabrication of thermoplastic-based composites. In this paper, a detailed literature review on the factors affecting the in situ consolidation process is presented. The models used to study the various aspects of the in situ consolidation process are discussed. The processing parameters that gave good consolidation results in past studies are compiled and highlighted. The parameters can be used as reference points for future studies to further improve the automated manufacturing processes.

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