Actively Controlled P-F Based Sliding Structures
This study summarizes about three years of research effort related to active control of sliding structures to both harmonic and strong earthquake type motions. This is the first time such...
Frictional Aspect of Rocking-Sliding of a Rigid Block with Surface Impact
During the very short time of impact between a rigid rectangular block and a rigid foundation, the interface pressure distribution varies with time in a complicated manner. Due to this...
Three-Dimensional Thermal Jump in Stratified Cooling Channel
This study is concerned with basic properties of three-dimensional thermal jumps. Temperature measurements obtained in three-dimensional thermal jumps are presented. The jumps analyzed...
On the Modelling of Damage Due to Volumic Variations in Cementitious Composites
Two kinds of volumic variations are considered. Those due to thermal gradients on hardened concrete and those due to hydration processes at early ages. Models based on damage mechanics...
High-Resolution Interwell Seismic Experiments in Sedimentary Formations
High-frequency interwell seismic data were acquired to examine full waveforms recorded in the pulsed mode and in the swept mode as well as to perform traveltime inversion tomography for...
Steady-State Nonlinear Heat Transfer in Multilayered Composite Panels
A two-dimensional computational model is developed for the nonlinear heat transfer in multilayered composite panels. The model is based on a first-order thermal lamination theory with...
Sensitivity of Lifeline Response to Models for the Spatial Incoherence of the Seismic Ground Motions
The sensitivity of the response of above-ground and buried lifelines to different models describing the spatial variability of the seismic ground motions is examined. It is shown that...
Slip Velocity and Temperature Jump in Flow over Rough Surface
The expressions for the slip velocity and the temperature jump are determined and used as the boundary conditions in the calculation of turbulent flow over rough surfaces. The slip velocity...
The Effective Stress Path for Soil at High Pressure
The effect of increasing stiffness in the soil skeleton on the effective stress path in undrained triaxial compression tests is experimentally examined and found to not be significant....
Unconfined Granular Materials Thermalized by Fluctuating Horizontal Surfaces
We calculate the solid fraction and granular temperature throughout assemblies of identical, smooth, inelastic spheres that are unconfined from above and thermalized from below by bumpy,...
Mechanics of Granular Materials at Very Low Effective Stress Levels
Gravity's influence on laboratory specimens of uncemented granular materials subjected to low effective stresses, makes it impossible to evaluate constitutive properties in an unambiguous...
Thermal Load for p-Version Laminated Elements
A p-version finite element formulation is presented for determining temperature stresses in laminated composite axisymmetric problems. Formulation for a rectangular axisymmetric p-version...
Inflation Concept Development for Inflatable Lunar Structures
Inflatable structures require mechanical equipment to initiate and maintain inflation. Several inflatable structural shapes and forms have been proposed by a number of different authors....
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...
Recent Developments of the Carbotek Process for Production of Lunar Oxygen
Carbotek and Shimizu Corporation are conducting joint development work on the further development of the Carbotek Process to produce oxygen from lunar ilemnite by hydrogen reduction. The...
Production of Oxygen by Electro-Reduction of Lunar Ores
Anorthositic Lunar ores contain approximately 42 wt. pct. of oxygen. An electrolytic dissociation of the ore can provide a rich source of gaseous oxygen with silicon, aluminum, calcium,...
Structural Design of the GN&C Navigation Base for the Space Station Freedom
The Space Station Freedom (SSF) pointing accuracy budget requires that the Guidance, Navigation and Control hardware maintain alignment within ? 0.1 degrees of arc. The ring laser gyros...
Orbital Construction of a NTR Mars Transfer Vehicle
This paper examines a reference Nuclear Thermal Mars Transfer Vehicle (NTMTV) in terms of on-orbit construction. The identification of subassemblies, payload manifesting, on-orbit connections,...
Transfer of Terrestrial Technology for Lunar Mining
Terrestrial mining equipment was evaluated for development of concepts and their application to lunar-based mining operations. The major operational differences between terrestrial and...
Thermal Investigation of a Large Lunar Telescope
Recent interest in construction of a large telescope on the Lunar surface (Nein and Davis, 1991; Bely, Burrows, and Illingworth, 1989) has prompted this feasibility study of a thermal...
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