Design Considerations for Small Artificial Islands in Franks Tract, California
Small, artificially-created islands may provide significant recreation and habitat benefits. Costs, however, can also be high. The initial dollar cost of creating an artificial island,...
Concrete for Sealing Voids in Rubble Structures
Permeability of rubble-mound breakwaters and jetties to sand transport and wave transmission results in increased costs for dredging and navigation. Guidance is provided for economically...
A New Era In Transportation
Its passage into law was about as smooth as a rush-hour traffic jam, but the surprising thing about the new Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) is that it...
Double Diamonds: New Brand for a Texas Bridge
Double diamond towers, distinctive as a cattle brand but tall as a 44 story building, have reached landmark status on the Texas Gulf Coast even though the bridge they will carry won't...
Rate-Dependent Plasticity Representation for Energy-Absorbing Materials
A three dimensional rate-dependent plasticity constitutive model is developed for rigid polyurethane foams. In the model, the material is decomposed into skeleton and solid matrix from...
Constitutive Modeling and Simulation of Energy Absorbing Polyurethane Foam Under Impact Loading
The compressive-stress strain response of polyurethane foam under uniaxial compressive impact loading has been studied. The development of a uniaxial constitutive model from strain rate...
Comparative Evaluation of Plasticity Theories Against Tension-Torsion Test at Finite Strain
This paper investigates and evaluates three hardening theories against a variety of nonproportional loading experiments on tubes made of annealed copper. It was concluded that the isotropic...
Size, Temperature and Rate Effects on the Fracture Toughness of Saline Ice
This paper presents the results of an extensive experimental study performed with the aim of investigating the effects of temperature, size and loading rate on the fracture toughness of...
Dynamic Effect of Sediment on Dam Hydrodynamics
The dynamic behavior of reservoir sediment during earthquakes is important to an analysis of dam safety when the depth of the water is seriously reduced by the sediment. While the dynamic...
On the Role of Dispersive Waves in Strain-Softening Media
Wave propagation in strain-softening continua is investigated numerically and analytically. It is argued that localisation which typically acts as a precursor of failure, can only be described...
Discrete Mechanics of Sediment Transport
Usually a granular medium is being represented by a continuous approximation in which the degrees of freedom of individual grains are averaged away in favor of a partial differential equation...
Erosion of Steep River Banks and Time Evolution Towards Equilibrium Channel Shape
A numerical analysis of the time evolution of straight river channels is presented. The bed and bank, material is taken to be coarse, non-cohesive and uniform in size. As a result of the...
Genesis: The Creation of a Lunar Base
A lunar basing scenario that utilizes lunar resources to manufacture lunar concrete modules is considered. An eleven year basing program, starting with initial robotic exploration and...
Conceptual Design of Modules for a Lunar Base
This paper describes the development of cubically shaped aluminum modules which could be variously arranged to form living and working quarters for a lunar base. The module components...
Uses for Lunar Crawler Transporters
This article discusses state-of-the-art crawler transporters and expresses the need for additional research and development for lunar crawlers. The thrust of the paper illustrates how...
A Proposed Methodology for Ranking Space Resource Utilization Processes
A recent survey paper on lunar manufacturing identified 26 initial steps previously proposed as primary routes for lunar processing. Most of these have not been studied in sufficient detail...
Phased Assembly of a European Space Station
This paper discusses a phased assembly approach for a proposed European Space Station utilising a series of constructional payloads that are delivered to orbit in an established sequence...
On-Orbit Assembly of Large Space Structures: A Mars Aerobrake Mock-up Study
As design requirements for space structures become larger in dimension, the issues of shipping and assembling these structures in space become more critical. One example of such a structure...
Cargo Transport to the Lunar Surface Using a Three Rotor Sling
The three rotor sling, a momentum transfer device, is described. The dynamics of multi-rotor systems are explained, and the three rotor system is shown to be favored over one and two rotor...
Ropeway Material Handling Systems for Lunar Mining Sites
The establishment of permanent lunar sites will be a requirement for future space explorations during early missions into space as well as long term. During all stages it will be necessary...
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