scholarly journals Study on the mechanical properties of outwash deposits with random structure method

2021 ◽  
Author(s):  
Chaojun Jia ◽  
Qiang Zhang ◽  
Mingfeng Lei ◽  
Jun Yu ◽  
Rubin Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spatial Distribution ◽  
Shear Zone ◽  
Large Scale ◽  
Physical And Mechanical Properties ◽  
Peak Stress ◽  
Displacement Curve ◽  
Random Structure ◽  
Direct Shear Tests ◽  
Outwash Deposit

ABSTRACT Outwash deposit is one of the major threats to the safety and stability of railway transit engineering in the Sichuan–Tibet area. In this paper, different samples of outwash deposits were prepared based on the random structure method, and a series of large-scale direct shear tests were carried out under different normal stresses. The influence of stone content and the spatial distribution of stone blocks on the physical and mechanical properties of outwash deposits were studied. The results show that with the increase of stone content, the shear stress-displacement curve changs from strain softening to strain hardening. The shear zone is larger, and its shape is more tortuous due to the movement and rotation of stone blocks. The internal frictional angle increases linearly while the cohesion diseases with the increase of stone content. The main influence of the spatial distribution of stone blocks on the mechanical properties of outwash deposits is the peak stress. The shear zone is mainly determined by the distribution of the stone blocks near the shear zone.

Use of Ash from the Incineration of Elephant Grass (Pennisetum purpureums shaum) into Clayey Ceramic

2012 ◽  
Vol 727-728 ◽  
pp. 993-998 ◽  
Author(s):  
A.M.F.D. Silva ◽  
L.S. Lovise ◽  
Sérgio Neves Monteiro ◽  
Carlos Maurício Fontes Vieira
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Large Scale ◽  
Chemical Characterization ◽  
Physical And Mechanical Properties ◽  
Linear Shrinkage ◽  
The Other ◽  
Industrial Processes ◽  
Elephant Grass ◽  
Calcium Compounds

Ashes generated in industrial processes are usually discarded and contribute to environmental pollution. Large scale incorporation into clayey ceramic products for civil construction, such as bricks and tiles, could be a permanent solution. Based on this rationale, this works has as its objective to characterize an ash waste from the incineration of elephant grass and to evaluate its incorporation into a clay to produce red ceramic. The waste was submitted to mineralogical and chemical characterization. Compositions were prepared with incorporation of the waste in amounts of up to 20 wt.% into the clay. Specimens were prepared by extrusion and fired in a laboratory furnace at 850°C. The physical and mechanical properties evaluated were: linear shrinkage, water absorption and flexural strength. The results showed that the waste is mainly composed of quartz and calcium compounds that sensibly reduce the linear shrinkage and does not change the other properties of the ceramic.

A Review of Rubber Oxidation

2005 ◽  
Vol 78 (2) ◽  
pp. 355-390 ◽  
Author(s):  
Gui-Yang Li ◽  
J. L. Koenig
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Spatial Distribution ◽  
Oxidative Degradation ◽  
Physical And Mechanical Properties ◽  
Oxidation Products ◽  
Unique Combination ◽  
The Past ◽  
Diffusion Limited ◽  
Rubber Compounds

Abstract The aging of rubber caused by oxidative degradation leads to the deterioration in the physical and mechanical properties of vulcanized rubbers. In an effort to improve the oxidative stability of rubbers and elastomers, considerable amount of work has been carried out over the past 50 years (especially in the most recent 5 years) in order to understand degradation modes and effects in rubber due to the action of oxygen and ozone in the air. Different mechanisms have been proposed to interpret the experimental data relative to the oxidation of rubber. The diffusion limited theory has been widely used in the literature and verified by many experiments. Various instrumental techniques have been utilized to characterize the oxidation and degradation and their mechanisms in rubber compounds. Recently, FTIR imaging has demonstrated a unique combination of spectral and spatial resolution which allows not only the identification of the oxidation products but also their spatial distribution from the oxygen penetrating surfaces. This critical review will cover the major developments in our understanding of the oxidation of rubbers.

scholarly journals Microstructural Features and Mechanical Properties after Industrial Scale ECAP of an Al 6060 Alloy

2010 ◽  
Vol 667-669 ◽  
pp. 1153-1158 ◽  
Author(s):  
Philipp Frint ◽  
Matthias Hockauf ◽  
T. Halle ◽  
G. Strehl ◽  
Thomas Lampke ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Zone ◽  
High Performance ◽  
Large Scale ◽  
Low Voltage ◽  
Tensile Tests ◽  
Industrial Applications ◽  
Industrial Scale ◽  
Opening Angle ◽  
Cross Sectional

Future applications of ultrafine-grained, high performance materials produced by equal-channel angular pressing (ECAP) will most likely require processing on an industrial scale. There is a need for detailed microstructural and mechanical characterisation of large-scale, ECAP-processed billets. In the present study, we examine the microstructure and mechanical properties as a function of location and orientation within large (50 x 50 x 300 mm³) billets of an Al 6060 alloy produced by ECAP (90° channel angle) with different magnitudes of backpressure. The internal deformation is analysed using a grid-line method on split billets. Hardness is recorded in longitudinal and cross-sectional planes. In order to further characterise the local, post-ECAP mechanical properties, tensile tests in different layers are performed. Moreover, low voltage scanning transmission electron microscopy observations highlight relevant microstructural features. We find that the homogeneity and anisotropy of mechanical properties within the billets depend significantly on the geometry of the shear zone. We demonstrate that deformation gradients can be reduced considerably by increasing the backpressure: The opening-angle of the fan-shaped shear zone is reduced from ψ ≈ 20 ° to ψ ≈ 7 ° when the backpressure is increased from 0 to 150 MPa. Backpressures of 150 MPa result in excellent homogeneity, with a relative variation of tensile mechanical properties of less than 7 %. Our investigation demonstrates that ECAP is suitable for processing homogenous, high performance materials on a large scale, paving the way for advanced industrial applications.

scholarly journals Influence of soil characteristics on working dynamics mining tral authority

2021 ◽  
pp. 46-51
Author(s):  
Pavlo Tkachyck ◽  
Alexandr Yemelianov
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Human Life ◽  
Physical And Mechanical Properties ◽  
Soil Surface ◽  
Armed Forces ◽  
Constant Weight ◽  
Before And After ◽  
Explosive Device ◽  
Direct Use

The safest way to clear mines and barriers, in terms of saving human life and health, is to clear them at the site. Minesweepers are being used for this purpose, and in recent years they have gained extensive research, which is aimed at the use of large-scale explosion technology. Existing minesweepers in the Armed Forces of Ukraine, as a rule, are old-fashioned, and have certain shortcomings that affect the efficiency of their direct use. These include, first of all, insufficient survivability and different efficiency of their use during demining of minefields with different types of soils: from sandy, loamy and gravel. The range of physical and mechanical properties of the latter is very wide, and therefore - for the operation of an explosive device (mine) requires different amounts of action on the soil surface. The modernized mine trawl neutralizing device in the form of a system of U-shaped rockers with disks at the end is proposed in the work. They, acting directly on the mine, or through a small layer of soil, cause it to explode, provided that the force on the latter is not less than the minimum value required for its disposal. The advantage of this type of mine trawl is that even if one of the working disks fails during the explosion, it is structurally relatively easy to replace it with another. The magnitude of the deepening of the neutralizing disks into the soil (at a constant weight of the mounted part of the trawl), as well as their dynamic action through the soil on the mine depends on the physical and mechanical properties of the soil. Therefore, for the case of, for example, clay or sandy soils during the movement of the trawl, it will be sufficient for the operation of the explosive device, at the same time for the coating of gravel - insufficient. In addition, the amount of deepening of the working disks in the soil depends on its humidity. The study of the influence of the main physical and mechanical characteristics of soils on the dynamics of the modernized mine trawl neutralizing device during movement along the minefield (before and after the mine explosion) is the subject of research, hence their relevance.

scholarly journals Substantiationofrules ofsimilarityofbreakingloadoftwistedfishinggear

2020 ◽  
Vol 0 (1) ◽  
pp. 38-45
Author(s):  
Alexander Alekseevich Nedostup ◽  
Pavel Nasenkov ◽  
Alexey Olegovich Razhev ◽  
Karina Konovalova ◽  
Sergey Fedorov
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Large Diameter ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Breaking Load ◽  
Full Scale ◽  
Fishing Gear ◽  
Scale Modeling ◽  
Polyamide Fibers

The article focuses on the problem of physical modeling of the physical and mechanical properties of fishing twisted filamentary materials, in particular, the most important one – the breaking load. The problems arise because of conducting full-scale experiments, particularly when the ropes of large diameter are used to build the rope parts of fishing gear. The solution to the problem of determining the breaking load on filamentary parts can be found by using specialized tensile testing machines and modern software, which is an effective tool for predicting the reliability and a resource of a gear part operating in difficult conditions of dynamic and shock loads. However, de-signing of fishing gear must begin with large-scale modeling, which will help to correctly calculate the physical and mechanical properties of the designed object using the well-known parameters of the full-scale material. The similarity rules of breaking load of fishing twisted filamentary gear used for the construction of industrial fishing tools will make it possible to model new elements of these tools without conducting full-scale experiments. At the same time, they will already contain solutions to problems associated with studying the dynamic processes, deformation, fracture, as well as the prediction of reliability and resource of the material. The technique proposed based on determining the scale of similarity of filamentary gear made of polyamide fibers, will help to simu-late various net and rope elements from filaments gear of various sizes and structures, instead of conducting energy-intensive experimental studies on ropes of large diameter.

Geomechanical Characterization of Faulted Rock Materials in Korea

2006 ◽  
Vol 321-323 ◽  
pp. 328-331 ◽  
Author(s):  
Yong Seok Seo ◽  
Chang Yong Kim ◽  
Kwang Yeom Kim ◽  
Kyoung Mi Lee
Keyword(s):  
Mechanical Properties ◽  
Rock Mass ◽  
Physical And Mechanical Properties ◽  
Mineralogical Composition ◽  
Rock Materials ◽  
Direct Shear Tests ◽  
Fault Gouges ◽  
Geomechanical Characterization ◽  
Mineralogical Assemblage

A faulted rock usually shows the swelling behavior because of clay minerals which consist of the fault gouges. It makes rock mass unstable and threatens the safety of structures built in rock mass. This study was aimed at clarifying characteristics of physical and mechanical properties of faulted rock materials. At first, microstructures and mineralogical composition associated with faulting in the fault gouge zones were analyzed by using X-ray diffractometry (XRD) and SEM microphotographs. Physical properties of the faulted rock materials from fields were measured in the laboratory. It is well known that the mechanical properties are sensitive to the mineralogical assemblage and are affected by the shapes, distribution and preferred crystallographic orientation of the components. Material and direct shear tests were also conducted on faulted rock materials under saturated and unsaturated conditions. The mechanical results were analyzed together with the analyzed result of XRD and SEM.

scholarly journals Review of Research on Physical and Mechanical Properties and Engineering Application of Metal Tailings

2022 ◽  
Vol 2148 (1) ◽  
pp. 012059
Author(s):  
Shengfu Wang ◽  
Lechen Yan ◽  
Kaixi Xue ◽  
Liang Lv ◽  
Dongjie Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Building Materials ◽  
Engineering Application ◽  
Physical And Mechanical Properties ◽  
Future Research ◽  
Tailing Dams ◽  
The Stability ◽  
Processing And Storage ◽  
And Storage

Abstract Processing and storage requirements for metal residues are becoming stricter to achieve the carbon neutralization target. The physical and mechanical properties of tailings affect the stability of tailing dams. Metal tailings can be used as secondary resources, and it is easy to pollute the environment under poorly managed conditions. Therefore, it is necessary and urgent to reuse these deposits such as iron tailings, copper tailings, zinc tailings et al. This article discusses the current research on the mechanical properties of metal tailings and its engineering application. Based on previous research, it is pointed out that there still needs more attention on the mechanical properties of metal tailing sands, especially under different conditions like dry-wet, freeze-thaw, dynamic loads and large-scale application. In the future, research on the filling of metal tailings as roadbed and new building materials will be one of the directions to solve the problem of tailing pond accumulation.

Development of 7%Ni-TMCP Steel Plate for LNG Storage Tanks

2011 ◽  
Author(s):  
Ryuichi Ando ◽  
Kazushige Arimochi ◽  
Tomoya Kawabata ◽  
Kazushi Onishi ◽  
Takahiro Kamo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Natural Gas ◽  
Large Scale ◽  
Steel Plate ◽  
Physical And Mechanical Properties ◽  
Rare Metal ◽  
Small Scale ◽  
Chemical Compositions ◽  
Nickel Steel ◽  
Storage Tanks

Demand of natural gas continues to increase in the recent years due to the rise of environmental issue and the drastic increase of crude oil price. These events led to the increase of constructions of Liquefied Natural Gas (LNG) storage tanks worldwide. The inner tank material for above ground LNG storage tanks have mostly been made of a 9% nickel steel plate over the last 50 years as it has excellent mechanical properties under the cryogenic temperature of −160deg-C. During this period, the LNG storage tanks made of 9%Ni steel plate have been operated safely at the many LNG export and import terminals in the world. Meanwhile, technologies of steel making, refinement, design, analysis, welding and inspection have been improved significantly and enabled enlarging volumetric capacity of the tank 2–3 times. There was a tendency for nickel price to increase in recent years. In such a circumstance lowering Ni content has focused attention on the 9%Ni steel as nickel is an expensive and valuable rare metal and a 7%Ni steel plate was eventually researched and developed by optimizing the chemical compositions and applying Thermo-Mechanical Controlled Process (TMCP). As a result, it was demonstrated that 7%Ni-TMCP steel plate had excellent physical and mechanical properties equivalent to those of 9%Ni steel plate. In order to evaluate fitness of the 7%Ni-TMCP steel plate and its weld for LNG storage tanks a series of testing was conducted. Several different plate thicknesses, i.e. 6,10,25,40 and 50 mm, were chosen to run large scale fracture toughness tests including duplex ESSO tests, cruciform wide plate tests as well as small scale tests. It was concluded that the 7%Ni-TMCP steel plate warrants serious consideration for use in LNG storage tanks. This paper reports details of the research and development of the 7%Ni-TMCP steel plate.

Model Test Studies of the Mechanical Properties of Pile - Soil Interface

2013 ◽  
Vol 392 ◽  
pp. 904-908 ◽  
Author(s):  
Cheng Hua Wang ◽  
Kui Jin ◽  
Chuan Zhan
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Concrete Surface ◽  
Direct Shear ◽  
Shear Tests ◽  
Direct Shear Tests ◽  
Vertical Bearing ◽  
Bearing Behavior ◽  
Soil Interface ◽  
Properties Of Soil

The study of the mechanical properties of pile-soil interface is an important aspect to research the vertical bearing behavior of piles. Currently special direct shear tests and special simple shear tests are usually used to study the mechanical properties of soil-structure interface. But those tests have shortcomings of difficulty in simulating the force properties of complex interface. In this paper, the mechanical properties of different interface between soil and concrete surface were studied through the large-scale direct shear tests.

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