New Approach to Interpret the Mechanical Behavior of Structured Soils

Due to the influence of soil structure, structured soils exhibit significantly different mechanical behavior compared to the reconstituted soils having the same material. In this work, a theoretical analysis focusing on the mechanical behavior of structured soils is presented. Based on the mechanical behavior of the structured soil, a newly defined variable structural index was used as a measurement of the integrity of soil structure based on the concept of intrinsic compression line of intact structured soils. Furthermore, a novel correlation for the variation in volume of structured soils is established using effective stress and newly defined structural index as the constitutive variables. The novel correlation provided interpretation about the mechanism of compression behavior of the structured soils. Afterwards, the proposed correlation for the variation in volume was extended to triaxial stress state in the framework of subloading surface to include the effect of overconsolidation. Comparisons between the predictions and experimental results validated the proposed constitutive model for structured soils.

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An Oedometer-Based Method for Preparing Reconstituted Clay Samples

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.719-720.193 ◽

2015 ◽

Vol 719-720 ◽

pp. 193-196

Author(s):

Jie Yin ◽

Yong Hong Miao

Keyword(s):

Mechanical Behavior ◽

Soil Structure ◽

Large Diameter ◽

Soft Clay ◽

Soil Samples ◽

Improved Method ◽

Structured Soils ◽

Reconstituted Soil ◽

Natural Clays

It is well known that the mechanical behavior of the natural intact soft clay is usually quite different from that of the reconstituted counterpart. Hence, how to predict the influences of soil structure on the mechanical behavior of natural clays is an important issue in geotechnical engineering.The mechanical behavior of structured soils can usually be quantitatively assessed based on the mechanical behavior obtained from corresponding reconstituted clays. The preparing method for reconstituted soils will affect the quality of reconstituted samples greatly, and therefore, affect their mechanical parameter. To guarantee the quality of reconstituted soil samples, a large diameter oedometer apparatus is developed. Also, an oedomer-based method for preparing reconstituted clay samples is proposed. Typical soft Lianyungang city clay from China is chosen to testify the methods and corresponding procedures. The feasibility of the improved method is confirmed by comparing its results with those of the normal oedometer test.

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Study of the relationship between hydro-mechanical soil behavior and microstructure of a structured soil

Earth Sciences Research Journal ◽

10.15446/esrj.v22n2.65640 ◽

2018 ◽

Vol 22 (2) ◽

pp. 91-101 ◽

Cited By ~ 1

Author(s):

Manoel Porfirio Cordão Neto ◽

Oisy Hernández ◽

Raydel Lorenzo Reinaldo ◽

Camila Borges ◽

Bernardo Caicedo

Keyword(s):

Mechanical Behavior ◽

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Water Retention Curve ◽

Soil Behavior ◽

Tropical Regions ◽

Structured Soils ◽

Bimodal Pore Size Distribution ◽

The Relationship

Structured soils, such as residual laterites or volcanic ashes, abound in tropical regions. The hydro-mechanical behavior of these soils is clearly related to their structure. New techniques based on microstructural studies constitute a powerful tool for investigating these soils. This work presents an experimental investigation that documents the relationships between the microstructure and the mechanical behavior of these soils. This study focuses on the microstructural behavior of Brasilia clay, a structured, highly porous tropical soil (n>50%) with a bimodal pore size distribution. The microstructure was investigated using pore size distribution analyses of different structural states and void ratios. The mercury intrusion porosimetry (MIP) technique was used to explore the pore size distribution of samples in various conditions, i.e., natural, compacted, slurry or consolidated states. Modeling of the pore size distribution curves was performed using the bimodal van Genuchten curve, which permits the linking of the pore size distribution curves (PSD) to the water retention curve. We observed that loading and compacting did not affect the micro-pores of this soil, and we conclude that the changes occurred entirely within the macro-pores.

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A New Approach for Scaling Aspirating Face Seal Aerodynamics

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4041515 ◽

2018 ◽

Vol 141 (3) ◽

Author(s):

Julius Wilhelm ◽

Corina Schwitzke ◽

Hans-Jörg Bauer ◽

Tue Nguyen

Keyword(s):

Mechanical Behavior ◽

Numerical Simulations ◽

The Self ◽

Experimental Results ◽

Face Seal ◽

Test Rig ◽

Labyrinth Seals ◽

New Approach ◽

Face Seals ◽

Self Adaptive

In the present paper, an approach for scaling the aerodynamics of advanced seals is presented. Modern advanced seals, such as a self-adaptive gas lubricated face seal, comprise elements that are commonly used in turbomachinery sealing. These are labyrinth seals and mechanical face seals. Parameters influencing the aerodynamical and mechanical behavior of each seals type are known. However, a combined methodology to scale the aerodynamics of the self-adaptive seal which consists of more than one element has not yet been published. The proposed methodology is applied to a model self-adaptive seal, and numerical simulations are performed to prove the validity of the approach. The new methodology ensures the transferability of experimental results at lab scale to engine conditions. Since the new approach allows scaling of self-adaptive seal tests, a new unique test rig will be designed accordingly.

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A New Approach for Scaling Aspirating Face Seal Aerodynamics

Volume 5B: Heat Transfer ◽

10.1115/gt2018-75812 ◽

2018 ◽

Author(s):

Julius Wilhelm ◽

Corina Schwitzke ◽

Hans-Jörg Bauer ◽

Tue Nguyen

Keyword(s):

Mechanical Behavior ◽

Numerical Simulations ◽

The Self ◽

Experimental Results ◽

Face Seal ◽

Test Rig ◽

Labyrinth Seals ◽

New Approach ◽

Face Seals ◽

Self Adaptive

In the present paper an approach for scaling the aerodynamics of advanced seals is presented. Modern advanced seals, such as a self-adaptive gas lubricated face seal comprise elements that are commonly used in turbomachinery sealing. These are labyrinth seals and mechanical face seals. Parameters influencing the aerodynamical and mechanical behavior of each seals type are known. However, a combined methodology to scale the aerodynamics of the self-adaptive seal which consists of more than one element has not yet been published. The proposed methodology is applied to a model self-adaptive seal and numerical simulations are performed to prove the validity of the approach. The new methodology ensures the transferability of experimental results at lab scale to engine conditions. Since the new approach allows scaling of self-adaptive seal tests, a new unique test rig will be designed accordingly.

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A New Approach to the Description of Mechanical Behavior of Polymer Glasses

International Journal of Polymeric Materials ◽

10.1080/00914039508012119 ◽

1995 ◽

Vol 29 (3-4) ◽

pp. 249-259 ◽

Cited By ~ 9

Author(s):

M. S. Arzhakov ◽

S. A. Arzhakov

Keyword(s):

Mechanical Behavior ◽

Polymer Glasses ◽

New Approach

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The O–C diagrams of minor planets − a new approach to modelling the rotation

International Astronomical Union Colloquium ◽

10.1017/s0252921100031407 ◽

1999 ◽

Vol 173 ◽

pp. 185-188

Author(s):

Gy. Szabó ◽

K. Sárneczky ◽

L.L. Kiss

Keyword(s):

Error Analysis ◽

Time Dependence ◽

Theoretical Work ◽

Minor Planet ◽

Minor Planets ◽

New Approach ◽

Preliminary Results ◽

Ccd Observations

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.

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Application of TEM to Deformation, Wear, and Fracture of Ceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052377 ◽

1974 ◽

Vol 32 ◽

pp. 472-473

Author(s):

B. J. Hockey

Keyword(s):

Wear Resistance ◽

High Temperature ◽

Mechanical Behavior ◽

Brittle Materials ◽

High Temperature Strength ◽

Wide Range ◽

Corrosive Environments ◽

Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

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