Evaluation of the Elasticity of Clay Soils

1973 ◽  
Vol 10 (4) ◽  
pp. 632-642
Author(s):  
Mohamed K. Elsamny
Keyword(s):  
Elastic Modulus ◽  
Clay Soils ◽  
Mathematical Treatment ◽  
Hopkinson Pressure Bar ◽  
Dynamic Approach ◽  
Soil Response ◽  
Preconsolidation Pressure ◽  
Pressure Bar ◽  
Available Information ◽  
The Relationship

A dynamic approach is used to evaluate the elasticity of clay soils. The experimental technique employed in the work is a modification of the Hopkinson pressure bar. Tests covering an appropriate range of stress levels were carried out on laboratory prepared specimens representing a variety of preconsolidation pressures. On the basis of the available information, using the Hopkinson bar technique, conclusions with regard to the relationship between the preconsolidation pressure of the soil tested and the elastic modulus for different rates of deformation are drawn. Also, the dynamic soil response of the soil tested and its relationship to the preconsolidation pressure are presented. A mathematical treatment of the relationship between the elastic modulus and the consolidation pressure is also presented which is verified experimentally using the pressure bar technique.

Wave Propagation in the Split Hopkinson Pressure Bar

1983 ◽  
Vol 105 (1) ◽  
pp. 61-66 ◽  
Author(s):  
P. S. Follansbee ◽  
C. Frantz
Keyword(s):  
Wave Propagation ◽  
Elastic Wave ◽  
Split Hopkinson Pressure Bar ◽  
Strain Curve ◽  
Leading Edge ◽  
Elastic Wave Propagation ◽  
Mathematical Treatment ◽  
Hopkinson Pressure Bar ◽  
Split Hopkinson ◽  
Pressure Bar

Elastic wave propagation in the split Hopkinson pressure bar (SHPB) is discussed with an emphasis on the origin and nature of the oscillations that often trail the leading edge of the pressure wave. We show that in the conditions of the SHPB test the pressure bars vibrate in the fundamental mode and that elastic wave propagation can be fully described mathematically. Excellent agreement is found between experimental results and predictions of the mathematical treatment. This suggests that dispersion effects in the pressure bars can be removed from the strain gage records, which reduces the magnitude of the oscillations in the resulting stress strain curve.

scholarly journals Study on Characteristic and Energy of Argillaceous Weakly Cemented Rock under Dynamic Loading by Hopkinson Bar Experiment

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3215
Author(s):  
Lingdong Meng ◽  
Lijun Han ◽  
Qingbin Meng ◽  
Kexiang Liu ◽  
Maolin Tian ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Dynamic Loading ◽  
Impact Velocity ◽  
Wave Amplitude ◽  
Impact Resistance ◽  
Strain Curve ◽  
Hopkinson Pressure Bar ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Pressure Bar

To study the mechanical properties of argillaceous weakly cemented rock under dynamic loading, a sample reconstituted and graded loading scheme is firstly designed, and then the reorganization rock sample is used as the research object. Using a Hopkinson pressure bar test, the responses of an argillaceous weakly cemented rock mass under different reorganization loads and different impact velocities is studied, and changes in specimen shape after impact are also analyzed. The study found that with increased of the recombination load, the amplitude of the transmitted wave increases. With increasing impact velocity, the rate of the increase in the incident wave amplitude is much larger than that of the transmission wave amplitude. The dynamic stress–strain curve can be divided into a compaction stage, an approximate linear elastic stage, a microcrack growth stage and a strain softening stage. The larger the reorganization load is, the less obvious the compression stage of the stress–strain curve is, and the greater the elastic modulus is. The peak strength and elastic modulus increase with increasing strain rate before 500 s−1. When the reorganization load is increased, the deformation decreases, and its impact resistance increases. With increasing impact velocity, the deformation of the specimen increases.

Effect of Specimen Width on the Contact State between the Three-Point Bending Specimen and Supports in Hopkinson Bar

2011 ◽  
Vol 462-463 ◽  
pp. 553-558
Author(s):  
Chun Huan Guo ◽  
Rui Tang Liu
Keyword(s):  
Parallel Line ◽  
Critical Value ◽  
Analysis Method ◽  
Hopkinson Pressure Bar ◽  
Contact State ◽  
Three Point Bending ◽  
Specimen Width ◽  
Loss Of Contact ◽  
Pressure Bar ◽  
The Relationship

The effect of specimen width on the contact state between the three-point bending (TPB) specimen and supports has been investigated with the apparatus of Hopkinson pressure bar using the analysis method of the propagation of stress wave. The results indicate that, the time for loss of contact decreases linearly with the increase of specimen width when the specimen width is less than a critical value, and the relationship between the time for loss of contact and the specimen width shows a parallel line to the abscissa when the specimen width is greater than the critical value.

K-MEANS CLUSTERING ALGORITHM BASED CLASSIFICATION OF SOIL FERTILITY IN NORTH WEST NIGERIA

2020 ◽  
Vol 4 (2) ◽  
pp. 780-787
Author(s):  
Ibrahim Hassan Hayatu ◽  
Abdullahi Mohammed ◽  
Barroon Ahmad Isma’eel ◽  
Sahabi Yusuf Ali
Keyword(s):  
Soil Fertility ◽  
Crop Yield ◽  
Clustering Algorithm ◽  
Soil Samples ◽  
North West ◽  
R Programming ◽  
Available Information ◽  
Northwest Region ◽  
The Relationship

Soil fertility determines a plant's development process that guarantees food sufficiency and the security of lives and properties through bumper harvests. The fertility of soil varies according to regions, thereby determining the type of crops to be planted. However, there is no repository or any source of information about the fertility of the soil in any region in Nigeria especially the Northwest of the country. The only available information is soil samples with their attributes which gives little or no information to the average farmer. This has affected crop yield in all the regions, more particularly the Northwest region, thus resulting in lower food production.  Therefore, this study is aimed at classifying soil data based on their fertility in the Northwest region of Nigeria using R programming. Data were obtained from the department of soil science from Ahmadu Bello University, Zaria. The data contain 400 soil samples containing 13 attributes. The relationship between soil attributes was observed based on the data. K-means clustering algorithm was employed in analyzing soil fertility clusters. Four clusters were identified with cluster 1 having the highest fertility, followed by 2 and the fertility decreases with an increasing number of clusters. The identification of the most fertile clusters will guide farmers on where best to concentrate on when planting their crops in order to improve productivity and crop yield.

Energetic relationships for crushing of soil clods

2006 ◽  
Vol 2 (1) ◽  
pp. 51-72
Author(s):  
István Patay ◽  
Virág Sándor
Keyword(s):  
Moisture Content ◽  
Specific Energy ◽  
Soil Moisture Content ◽  
Energy Requirement ◽  
Clay Content ◽  
Clay Soils ◽  
Rigid Support ◽  
Soil Plasticity ◽  
Specific Energy Requirement ◽  
The Relationship

Clod crushing is a principal problem with soils of high clay content. Therefore, there is a need for determining the conditions for clod breaking and clod crushing. The objective of the work was to develop a special purpose tool for single clod breaking both by rigid support of the clod and by a single clod supported by soil and to develop a machine for clod crushing. Furthermore, the purpose was to determine the relationship between the specific energy requirement for clod crushing in the function of soil plasticity and the soil moisture content by the means of the developed tool and machine. The main result of the experiments is summarized in a 3D diagram where the specific energy requirement for soil clod crushing is given in the function of the moisture content and the plasticity index for different clay soils.

Analysis of the Impact of the Frequency Range of the Tensometer Bridge and Projectile Geometry on the Results of Measurements by the Split Hopkinson Pressure Bar Method

2013 ◽  
Vol 20 (4) ◽  
pp. 555-564 ◽  
Author(s):  
Wojciech Moćko
Keyword(s):  
Test Bench ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Deformation ◽  
Spectral Width ◽  
Hopkinson Pressure Bar ◽  
Computing Environment ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
The Impact ◽  
Bench Model

Abstract The paper presents the results of the analysis of the striker shape impact on the shape of the mechanical elastic wave generated in the Hopkinson bar. The influence of the tensometer amplifier bandwidth on the stress-strain characteristics obtained in this method was analyzed too. For the purposes of analyzing under the computing environment ABAQUS / Explicit the test bench model was created, and then the analysis of the process of dynamic deformation of the specimen with specific mechanical parameters was carried out. Based on those tests, it was found that the geometry of the end of the striker has an effect on the form of the loading wave and the spectral width of the signal of that wave. Reduction of the striker end diameter reduces unwanted oscillations, however, adversely affects the time of strain rate stabilization. It was determined for the assumed test bench configuration that a tensometric measurement system with a bandwidth equal to 50 kHz is sufficient

ANALISIS PENGARUH EKSPOR TERHADAP PERTUMBUHAN EKONOMI INDONESIA

2017 ◽  
Vol 11 (1) ◽  
pp. 1-20
Author(s):  
Ari Mulianta Ginting
Keyword(s):  
Economic Growth ◽  
Export Performance ◽  
Descriptive Analysis ◽  
Correction Model ◽  
Administration System ◽  
Long Run ◽  
Short Run ◽  
Available Information ◽  
Increasing Trends ◽  
The Relationship

Ekspor merupakan salah satu faktor terjadinya peningkatan pertumbuhan ekonomi suatu negara, sejalan dengan hipotesis export-led growth (ELG). Penelitian ini menganalisis perkembangan ekspor dan pertumbuhan ekonomi Indonesia periode kuartal I 2001 sampai dengan kuartal IV 2015. Penelitian ini menggunakan analisis deskriptif dalam menggambarkan perkembangan pertumbuhan ekonomi serta ekspor dan analisis kuantitatif metode Error Correction Model (ECM) dalam menganalisis efek jangka panjang dan jangka pendek dari ekspor terhadap pertumbuhan ekonomi. Pada periode penelitian, data yang ada menunjukkan bahwa ekspor dan pertumbuhan ekonomi Indonesia sama-sama mengalami peningkatan. Hasil regresi ECM menunjukkan bahwa ekspor memiliki pengaruh yang positif dan signifikan secara statistik terhadap pertumbuhan ekonomi Indonesia, yang mendukung hipotesis bahwa ELG berlaku untuk Indonesia. Berdasarkan hasil penelitian ini, maka untuk mendorong pertumbuhan ekonomi Indonesia diperlukan peningkatan kinerja ekspor Indonesia. Peningkatan kinerja ekspor Indonesia dapat dilakukan dengan berbagai cara, salah satunya adalah dengan perbaikan sistem administrasi ekspor, peningkatan riset dan pengembangan produk Indonesia, peningkatan sarana dan prasarana infrastruktur, stabilitas nilai tukar dan perluasan pasar non tradisional, termasuk perbaikan struktur ekspor komoditas. Export is one of the factors behind the economic growth which is in line with the export-led growth hypotesis (ELG). This research analyzes the relationship between economic growth and export of Indonesia during first quarter of 2001 until fourth quarter of 2015. It employs descriptive analysis to describe export movement and economic growth during the study period and ECM model to analyze the long run and the short run effects of export on the economic growth. The available information indicated that, during the study period, both export and economic growth showed similar increasing trends. The result of the ECM model revealed that export had a positive and statistically significant relationship with the economic growth, supporting the hypotesis of ELG in Indonesia. Hence, to accelerate economic growth, efforts are required to boost the export performance in Indonesia. The Export performance can be increased by several way, such as improving the export administration system, increasing the research and development of Indonesian products, improving the facilities and infrastructure, exchange rate stability and the non-tradisional markets expansion, and including improvement of the export commodity structure.

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