Effect of stress anisotropy on deformation and particle breakage of silica sand at high-pressure compression tests

2022 ◽  
Vol 316 ◽  
pp. 125835
Author(s):  
Tao Zhang ◽  
Chi Zhang ◽  
Tingting Luo
Keyword(s):  
High Pressure ◽  
Particle Breakage ◽  
Silica Sand ◽  
Compression Tests ◽  
Stress Anisotropy

Experimental study of one-dimensional compression creep in crushed dry coral sand

2020 ◽  
Vol 57 (12) ◽  
pp. 1854-1869
Author(s):  
Jiabo Wang ◽  
Pengxian Fan ◽  
Mingyang Wang ◽  
Lu Dong ◽  
Linjian Ma ◽  
...  
Keyword(s):  
Relative Density ◽  
Deformation Behaviour ◽  
Particle Breakage ◽  
Time Dependent ◽  
Silica Sand ◽  
Lateral Strain ◽  
Test Results ◽  
Compression Tests ◽  
One Dimensional ◽  
Coral Sand

Understanding the time-dependent deformation behaviour of backfill coral sand is important to the long-term stability of engineering facilities built on reefs and reclaimed land. A series of one-dimensional compression tests (with no lateral strain) were carried out on crushed coral sand with a variety of grading and relative densities (50%, 70%, and 90%) sampled from the South China Sea. Axial pressure was applied in stepped loading form: 100, 200, 400, 800, and 1600 kPa. Each level loading was applied for 3 days and then completely unloaded until the deformation was stable, after which the next loading level was applied. The test results indicate: (i) the deformation of coral sand is much larger than silica sand and involves a larger proportion of time-dependent and plastic deformation; (ii) the total deformation of coral sand and proportion of irreversible deformation decreases as the relative density increases; (iii) coral sands of better grading tend to deform less in total and have larger proportions of elastic and time-dependent deformation; and (iv) the grading of coral sand changes during the deformation process due to particle breakage. Based on the test results, the relationships between particle breakage and pressure, relative density, and grading, as well as the grain-scale mechanism of the deformation, are discussed.

Detailed amount of particle breakage in nonuniformly graded sands under one-dimensional compression

2020 ◽  
Vol 57 (8) ◽  
pp. 1239-1246 ◽  
Author(s):  
Yu Peng ◽  
Xuanming Ding ◽  
Yang Xiao ◽  
Xin Deng ◽  
Weiting Deng
Keyword(s):  
Size Range ◽  
Particle Breakage ◽  
Silica Sand ◽  
Relative Mass ◽  
Compression Tests ◽  
Compression Pressure ◽  
One Dimensional ◽  
Coral Sand ◽  
Linear Relationships ◽  
Different Color

The coexistence of broken and unbroken grains in each size range can disturb the assessment of actual amount of particle breakage. In this study, a series of one-dimensional compression tests were carried out on three kinds of coral sands and a silica sand to clarify the detailed amount of particle breakage for nonuniformly graded sands. Before the compression tests, both coral and silica sand assemblies were divided into different grain-size groups and dyed in different colors, then mixed as nonuniformly graded packings. After the compression, grains of different color in each size range were discerned quantitatively by implementing particle images segmentation on images of grains. Results show that the extent of particle breakage was found to be larger than the change in relative mass percentage in most size ranges, and the new “absolute particle breakage” wd for each size range satisfied linear relationships with the logarithmic value of compression pressure. Compared with silica sand, coral sand has weaker abrasion under high pressure due to the strong interlock among grains. New breakage indexes of sand samples, based on detailed particle breakage, are proposed. The detailed particle breakage could be useful for proposing a breakage-dependent constitutive model of crushable granular soils.

scholarly journals The influence of particle breakage on stress-dilatancy relationship for granular soils

2019 ◽  
Vol 92 ◽  
pp. 09004 ◽  
Author(s):  
Zenon Szypcio
Keyword(s):  
Internal Energy ◽  
Stress Level ◽  
Triaxial Compression ◽  
Volumetric Strain ◽  
Stress Path ◽  
State Theory ◽  
Particle Breakage ◽  
Compression Tests ◽  
Particle Crushing ◽  
Soil Gradation

The influence of particle breakage on soil behaviour is important from theoretical and practical perspectives. Particle breakage changes the internal energy in two ways. First, internal energy is consumed for particle crushing and second, the internal energy changes because of additional volumetric strain caused by particle crushing. These two effects may be quantified by use of Frictional State Theory. The analysed drained triaxial compression tests of Toyoura sand, gravel and Dog's Bay sand at different stress level and stress path revealed that the effect of particle breakage is a function of soil gradation, strength of soil grains, stress level and stress path.

scholarly journals Drop of Pressure Behavior of Open-Cell Aluminum Foams at High Pressure Flow

2021 ◽  
Vol 19 (6) ◽  
pp. 603-621
Author(s):  
Manuel F. Azamar ◽  
Ignacio A. Figueroa ◽  
Gonzalo Gonzalez ◽  
Ismeli Alfonso
Keyword(s):  
High Pressure ◽  
Room Temperature ◽  
Critical Conditions ◽  
Physical Parameters ◽  
Compression Tests ◽  
Aluminum Foams ◽  
Open Cell ◽  
Geometrical Properties ◽  
Pressure Behavior ◽  
Structural Capacity

Open-cell aluminum foams were produced by the replication technique in three different pore sizes, ranging from 0.71 to 4.75 mm. The manufactured specimens were physically characterized, determining their porosity, relative density, pores per inch and interconnection windows density. A new experimental design is proposed in order to assess the drop of pressure behavior resulting from the injection of gasoline additive at increasing high pressure intervals, ranging from 200 to 25,000 psi, reproducing the tests at room temperature and 200 °C. The regime governing the flow through the investigated samples was determined as a function of flowrate and the foams physical properties. The structural capacity of open-cell Al foams to conduct highly pressurized flow was evaluated by means of compression tests. It was found that at room temperature, the drop of pressure behavior is strongly associated to physical parameters, whilst at 200 °C, dimensional and geometrical properties are negligible. In addition, in this investigation, it is presumed that the studied foams have the structural capacity to conduct fluids at critical conditions of pressure and temperature.

scholarly journals Phenol-Furfural Resin/Montmorillonite Based High-Pressure Green Composite from Renewable Feedstock (Saccharum munja) with Improved Thermo-Mechanical Properties

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1562 ◽  
Author(s):  
Muhammad Zeeshan Asad ◽  
Azhar Mahmood ◽  
Syed Tasweer Hussain Shah
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Phenol Formaldehyde ◽  
Testing Machine ◽  
Montmorillonite Clay ◽  
Plant Residue ◽  
Formaldehyde Resin ◽  
Compression Tests ◽  
Green Composite ◽  
Saccharum Munja

This research endeavour aimed to explore the potential of a native, nonedible and low market value plant feedstock, i.e., Saccharum munja for green synthesis of woodware materials and improve its features by incorporating an economical blending material. A significant amount of furfural, i.e., 58%, was extracted from Saccharum munja through the modified acid digestion method. Extracted furfural was reacted with phenol to prepare phenol-furfural resin, an alternative to phenol-formaldehyde resin but with no harmful effects for humans. The synthesized resin was also blended with montmorillonite clay after modification via Dimethyl Sulfoxide (DMSO) treatment for improved thermo-mechanical properties. These resins and composites were characterized by XRD, SEM, and FTIR spectroscopy. Resultant resins and composites were further employed as a binding agent to make high-pressure composite from leftover plant residue by hot-press method. The resultant product was subjected to TGA analysis and furnished high value of degradation temperature (Tdeg), i.e., 607 °C. Prepared high-pressure composite samples were mechanically tested through compression tests by Tinius Olsen Testing Machine and hardness tests by Rockwell Hardness Tester. Its tensile strength value was 58.3 MPa while hardness value was found to be 64 RHB which was greater than mild copper with hardness value 48.9 RHB. Thus, green high-pressure composite material was successfully developed by employing Saccharum munja and montmorillonite clay while no toxic resin was used, nor was any residue left over.

Aluminium Self-Piercing Rivet's Failure: Testing and Numerical Analyses

2014 ◽  
Vol 541-542 ◽  
pp. 1355-1359 ◽  
Author(s):  
Nguyen Hieu Hoang ◽  
Magnus Langseth
Keyword(s):  
Finite Element ◽  
High Pressure ◽  
Fracture Behaviour ◽  
Shear Fracture ◽  
Calibration Procedure ◽  
Finite Element Code ◽  
Failure Model ◽  
Compression Tests ◽  
Tension Tests ◽  
Riveting Process

In the present study, the behaviour of aluminium rivets in alloy AA7278-T6 during the riveting process when used to join two aluminium plates was investigated experimentally and numerically. It was observed by Hoang et al. that a rivet in alloy AA7278-T6 may fracture in shear when undergoing high pressure during the riveting process. A damage-based failure model was adopted for studying the shear fracture behaviour of the rivet. A calibration procedure of the damage parameters was suggested based on two tests (i.e. material tension tests and rivet compression tests). The model was implemented in the finite element code LS-DYNA as a user-defined subroutine. Numerical results showed that the model seemed to be able to capture the shear fracture mode in the rivets as observed in the tests.

Sign in / Sign up

Export Citation Format

Share Document