Vacuum Melting and Mechanical Testing of Simulated Lunar Glasses
Lunar silicate glasses may possess superior mechanical properties compared to terrestrial glasses because the anhydrous lunar environment should prevent hydrolytic weakening of the strong...
Strength and Fracture of Glass in the Lunar Environment
Due to the lack of water on the moon, the effects of hydrolytic depolymerization - stress corrosion cracking - will be nonexistent in glasses produced and used on the moon. This would...
Mechanical Properties of Compacted Lunar Simulant Using New Vacuum Triaxial Equipment
Mechanical stress-strain-strength properties of Arizona Lunar Simulant (ALS) are investigated by using a newly developed vacuum triaxial device that allows compaction under different initial...
Composite Materials for Structures on Planetary Surfaces
Development of structures for planetary surface environments depends upon the use of the most appropriate materials. Advanced composite materials are apparently the best candidates for...
Comparison of Micromechanical Models for Elastic Properties
The effective elastic properties for unidirectional composites, as predicted by several analytical micromechanical models are compared for glass/epoxy and graphite/epoxy. A brief review...
Regolith Dynamics
Due to the differences of the gravitational accelerations of the Earth and Lunar environments, geotechnical engineering must be applied differently in the two environments. This study...
Combustion Synthesis of Advanced Materials
The combustion synthesis of ceramic-metal composites using an in-situ liquid infiltration technique is described. The effect of varying the reactants and their stoichiometry to provide...
Principles of Control for Robotic Excavation
Excavation can be considered one of the most unstructured problems in the construction environment. On one hand, many technologies have been developed in the past to build shelters using...
The Lunar Transit Telescope (LTT): An Early Lunar-Based Science and Engineering Mission
The moon is an excellent spacecraft, with mass, rotational, thermal and orbital properties which make its utilization as a base for astronomical observations superbly reasonable. The Lunar...
Laboratory Evaluation of Footings for Lunar Telescopes
Presented here are the results of laboratory experiments with different footing shapes for lunar telescopes. These experiments used a variety of soils including some to simulate regolith...
Plot-scale Field Experiment of Surface Hydrologic Processes with EOS Implications
Plot-scale hydrologic field studies were initiated at NASA Marshall Space Flight Center to a) investigate the spatial and temporal variability of surface and subsurface hydrologic processes,...
Evacuation Modeling Near a Chemical Stockpile Site
Dynamic evacuation modeling was used as an aid in emergency response planning by Tooele County, Utah, location of the United States' largest stockpile of unitary chemical weapons, The...
Better Cover-Ups
Designing the final cover for a solid waste landfill or remediation site is often trickier than designing its lining because a cover will undergo more unpredictable stress and distress...
Earthquake Considerations in Earth Dam Design
In 1963, the writer was engaged by the State of California Department of Water Resources to make a study of the influence of the hazard of earthquakes on the design of embankment type...
Piping in Earth Dams of Dispersive Clay (Paper introduced by Norman L. Ryker)
In 1971 Jim Sherard was engaged to investigate the common failure of a group of Soil Conservation Service (SCS) floodwater retarding earthfill dams built between 1957 and 1970, eleven...
Land Use, Transportation and Air Quality Relationships
Increasing land development densities and reducing suburban sprawl is frequently considered as a tool to reduce vehicle miles of travel and resultant air pollution emissions. Two studies...
Variability Response Functions and Stochastic Field Discretization in Stochastic Finite Element Methods
Stochastic systems whose mechanical properties vary spatially are investigated in the present paper. The stochastic response variability of the systems is characterized by means of the...
Dynamic Response of Uncertain Two-Dimensional Structures
A concept for the reliability analysis of structures with uncertain elastic and mass properties is presented. Its applicability is shown by means of a numerical example. The results are...
Surface Motion Due to Stochastic Plane Sources in a Layered Medium
To simulate the ground motion in the near field, a seismic fault is modeled as a two-strip plane. The width of each strip is so thin that the rupture process of the strip can be described...
Evaluation of Expansive Clay Soils in Tucson, Arizona
Research was conducted to investigate the mineralogy, engineering properties, and regional distribution of expansive clay soils in Tucson, Arizona. Data derived from X-ray diffraction...
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