Constitutive Equation for Granular Material by Hypoelasticity
Constitutive equations for soil based upon the incremental theory of hypoelasticity are proposed in this paper to account for the stress path dependency and dilatant behavior of soil....

The Morphology and Dynamics of Natural and Laboratory Grain Flows
Artificially generated sand flows that display considerable similarity with field examples on eolian dunes allow documentation of the relationships between grainflow scales and the characteristics...

Computational Gradient Plasticity
The inclusion of higher-order deformation gradients is of paramount importance for properly describing strain localization within the framework of continuum mechanics. In this contribution...

Predicting the Performance Limits of Soil-Culvert Systems
A finite element model for elastic plastic large deformation analysis of soil-culvert systems is presented. Predictions of this numerical model are in good agreement with failure tests...

Eigenproperties of a Twisted, Nonuniform Rotating Beam by the Finite Element Method
A initially twisted blade with nonuniform properties along the length, is rotating with constant angular velocity about an axis perpendicular to it's elastic axis. The blade is modeled...

Modeling Bond Stress-Slip of Reinforcing Bars Embedded in SIFCON
A brief description is given of the mechanisms associated with the bond shear stress versus slip response of deformed reinforcing bars embedded in slurry infiltrated fiber concrete (SIFCON)....

Pattern Formation and Time-Dependence in Flowing Sand
The authors present results for a number of experiments on flowing granular materials and a novel cellular automata model for the flow of these materials when the grains are long and thin....

Laboratory Testing of Mechanical Rock Bolts
An analytical solution to a boundary value problem of a clamped cylindrical panel with anti-symmetric angle-ply laminations subjected to transverse loads is presented. Sanders' kinematic...

Cylindrical Fabric-Confined Soil Structures
Using the local soil as a structural material can greatly reduce the transport requirements for constructing Lunar and Martian surface structures. A fabric-soil structural concept which...

The Small Mars Rover
Mars rover is one of the principal technical means intended for studying the surface of Mars. The first Mars rover was delivered to the Mars surface in 1971 and was designed for studying...

Experimental Study of Underground Exploration by Auger Boring on a Mars Rover
A system study was conducted on the possibility of exploring Mars using a Mars Rover, and particular efforts were focused on the underground exploration of Mars by an auger boring machine....

Indigenous Planetary Construction Material Through Soil Modification
This paper will discuss the theory of soil modification and its potentials for producing planetary construction materials. The authors will also present the results of prelimnary experriments...

Mechanical Properties of Lunar Soil and Simulants
Investigation of the physical and mechanical properties of lunar soil carried out by the USSR and the USA; both in situ and on returned samples, has resulted in considerable information...

Structural Materials from Lunar Simulants Through Thermal Liquefaction
Thermal liquefaction that allows development of intermediate ceramic composites from a lunar simulant with various admixtures is used to develop structural materials for construction on...

In-situ Release of Solar Wind Gases from Lunar Soil
A concept is described which has the potential to perform the in-situ heating of the lunar regolith in order to release the solar wind gases. The poor thermal conductivity of the lunar...

Hydrogen Reduction of Lunar Soil and Simulants
Carbotek, Inc., and the Energy and Environmental Research Center (EERC) are cooperating on further development of the Carbotek process to produce oxygen from lunar ilmenite by hydrogen...

Lunar Oxygen ? The Reduction of Glass by Hydrogen
The direct reduction of volcanic glass by hydrogen has been proposed as a method of extracting oxygen from the lunar soil. Experiments using lunar simulant glasses reacted with flowing...

A Modified Sulfate Process to Lunar Oxygen
A modified sulfate process which produces oxygen from iron oxide-bearing minerals in lunar soil is under development. Reaction rates of ilmenite in varying strength sulfuric acid have...

Steady State Composition with Low Fe?+ Concentrations for Efficient O2 Production by Magma Electrolysis of Lunar Soils
Parameters are estimated for a hypothetical, well stirred, continuous-feed electrolytic cell that converts 20% of a lunar soil feedstock to O2 gas,...

Beneficiation of Lunar Rocks and Regolith: Concepts and Difficulties
Considerations of the resources which can provide feedstocks of ilmenite, glass, agglutinates, anorthite, etc. at a lunar base require an appreciation of the geology of the situation....

 

 

 

 

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