Static and Dynamic Properties of Gravelly Soils
The behavior of gravelly soils has been the focus of much research in recent years. Large-scale penetration and triaxial tests, shear-wave velocity measurements, insitu freezing and sampling,...
Human Extender: A Material Handling System
A human's ability to perform physical tasks is limited by physical strength, not by intelligence. `Extenders' are a class of robot manipulators worn by humans to augment human mechanical...
Real-Time Control for a Robotic Rebar Bender
Job conditions and variability in the properties of the stock material combine in a rebar bending operation to create a challenging environment for a robotic bender. This paper reports...
On the Dynamics and Control of Flexible Orbiting Systems: An Approach with Application
A relatively general formulation for studying the dynamics and control of an arbitrary spacecraft, with interconnected flexible, deployable and articulating structural members, is reviewed...
Improving Dynamic Finite Element Models Using Test Data
A structural optimization based method was developed to improve the finite element model to achieve good agreement with the test results. The modal displacements at critical locations...
Thermoelastic Theory of Cylindrical Sandwich Shells with Piezoelectric Sensors or Actuators
Cylindrical sandwich shells with piezoelectric longitudinal and ring elements bonded to the outer and inner surfaces are considered in this paper. Thermal effects are included in the analysis,...
Large Deformation Theory Using Truncated Rotations
Today's aerospace industry has advanced to the point of using optimum design techniques in virtually all applications. In structural elements, orthotropic fiber composite materials have...
Mechanics of Curved Fiber Bundles in Composites
Fiber undulations are inherent to manufacturing processes like braiding and filament-winding, and sometimes occur as defects in other composite structures. This paper summarizes the status...
Hygrothermal Effects in Composite Sandwich Panels
The macromechanical analysis of a composite panel with laminate facings and a honeycomb core is carried out by taking into account mechanical and hygrothermal loads. In this analysis the...
Late Stage Damage in G30-500/PMR-15 Laminates
Damage progression has been studied experimentally under tension using [02/906]s...
Thermal Cycling of Thin and Thick Ply Composites
An experimental study was conducted to determine the effects of ply thickness in composite laminates on thermally induced cracking and changes in the coefficient of thermal expansion (CTE)....
Development, Testing and Modeling of Ceramic Composites for Lunar Applications
The procedure referred to as thermal liquefaction allows production of Intermediate Ceramic Composites (ICC) from lunar simulants with various admixtures. For their use as structural materials...
Methods to Mitigate Thermally Induced Distortion
The purpose of this paper is to show the magnitude of bending on the Space Station Freedom Navigation Base as induced by thermal expansion and contraction over the operating range -45...
JSC-1: A New Lunar Soil Simulant
A new lunar soil simulant, JSC-1, has been developed and characterized under the auspices of the NASA Johnson Space Center. This simulant was produced in large quantities to satisfy the...
A Simple Method of Producing Lunar Soil Simulants for Engineering Studies
This paper suggests that it is possible to obtain large quantities of simulated lunar regolith that can be used for feasibility studies of lunar base construction and excavation machinery...
Reservoir Estimates for the Sulpicius Gallus Region
Estimates presented here show that 1.1?109 metric tons of oxygen could of produced from one of the enriched areas that have been detected by spectrographic...
Terrestrial Analogs: Implications for Lunar Lava Tubes
Earlier work has demonstrated that lava tubes did form on the Moon. Comparison of terrestrial lava tubes to their lunar counterparts suggest that they are very similar despite the order...
Lunar Oxygen Production - A Maturing Technology
Research on oxygen production from lunar rock and soil has made significant progress in the past two years. An extensive series of experiments on natural and synthetic analogs has concentrated...
Lunar Oxygen Production in a Hydrogen Cold Plasma
This paper examines the concept of oxygen production from unbeneficiated lunar regolith using a non-equilibrium or 'cold' hydrogen plasma. An experimental investigation has indicated that...
Carbon Formation Theory for Space Oxygen Processes
Production of oxygen from the Martian atmosphere or lunar soil and the recovery of oxygen in manned space environments may include carbon formation from CO as a unit process. Thermodynamic...
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