Computer Simulation of Dry Layered Granular Flow Down an Incline Composed of Grains
Experiments show that gravity-driven dry granular flows are essentially layered for smooth spheres. This paper describes layer-to-layer interaction in the flow. Assuming two-dimensional...
Distributed Failure Analysis, Fallacies and Remedies
In the past, two distinctly different approaches - smeared and discrete failure descriptions have been utilised to capture failure mechanisms in solids and structures. These two approaches...
An Elastoviscoplastic Model for High Strength Concrete
An elastoviscoplastic model of overstress type is proposed for high-strength concrete in this study. With its viscosity parameters determined with experimental data from the split-Hopkinson-pressure-bar...
Stability of Systems of Rigid Bodies by Bounding Theorems
The stability of systems of systems of rigid bodies subjected to conservative and dissipative forces is investigated by considering the minimization of a work function subject to the kinematic...
Inverse Problems in Biomechanics
The FEM (Finite Element Method) is a powerful numerical technique in solving boundary value problems in Biomechanics, which are difficult to analyze by other closed form or numerical procedures...
Analysis of Two Lunar Oxygen Production Processes
Frequently, chemical engineers must evaluate processes, design systems, and size equipment based on a chemical or physical reaction without the benefit of laboratory data or previous industrial...
Assessing Lunar Resources with Remote Sensing
Four strategic architectures have been identified as part of the U.S. Space Exploration Initiative (SEI) to achieve U.S. goals with respect to the Moon. One of these architectures, space...
Modeling and Analysis of Doubly Curved Aerobrake Truss Structures
Recent studies have indicated that vehicles designed for a piloted mission to Mars may have their initial Earth Orbit mass reduced by nearly a factor of two if aerobraking is used rather...
Design Criteria for an Underground Lunar Mine
Underground excavation and construction techniques have been well developed terrestrially and provide an attractive option for lunar mining and habitat construction. The lunar mine, processing...
Optimum Design of Laminated Composites
The increased demand for high strength, light weight materials that function successfully in high temperature environments has caused the effective development of laminated composites...
Telerobotic Field Geologist: Preliminary Results of a Feasibility Study
We conducted three laboratory studies to explore the feasibility of developing a telerobot to perform planetary field geology. In all, 72 college students attempted to match each of 15...
Modular Robot Testbed
One approach to non-terrestrial construction involves the use of small, inexpensive, modular robots rather than expensive one-of-a-kind construction tools. The Modular Robots Testbed at...
The Virtual Mission: A Step-Wise Approach to Large Space Missions
The new Virtual Mission concept will provide NASA's Science Program with a powerful new, 'go-as-you-pay,' flexible, and resilient way of accomplishing its science observing program. The...
An Operational Evaluation Process for Long-Duration Mission Habitats in Space
In preparation for long-duration manned spaceflight into the 21st Century, the ergonomical and psychological aspects of space habitat architectures are being investigated in Europe. Used...
A Facility for Training Space Station Astronauts
The Space Station Training Facility (SSTF) will be the primary facility for training the Space Station Freedom astronauts and the Space Station Control Center ground support personnel....
Geographical Information System (GIS) Technology in Global Environmental Evaluation?An Overview
The Land Analysis Team at the Construction Engineering Laboratory is enhancing the GRASS software package to deal with global environmental questions. CERL has implemented the basic software,...
The Wide-Angle Optoelectronic Stereo Scanner WAOSS for the Soviet Mars 94/96 Missions
The Wide-Angle Optoelectronic Stereo Scanner WAOSS is anticipated for the Soviet Mars 94/96 missions. Starting from the tasks of WAOSS as a part of the TV complex ARGUS, the paper describes...
Object Oriented Spacecraft Architecture
This paper describes an architecture for simplifying the spacecraft design and maintenance process: Object Oriented Spacecraft Architecture. Like object oriented programming, the strategy...
Using Simulation to Evaluate On-Orbit Construction Operations
As the NASA Space Exploration Initiative (SEI) program contemplates a permanent presence on both the Lunar and Martian soil, the necessity for On-Orbit Construction of the Earth-to-Lunar/Martian...
Characteristics of High-Speed Runway Exits for Airport Design
This paper addresses some of the geometric design and operational characteristics of high-speed runway exists. Lateral and longitudinal runway constraints limiting the use of high-speed...
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