Medical Care on the Moon
Eventually, people will return to the Moon to stay for prolonged periods of time. When they do, they will be exposed to a wide range of threats to their health including, decompression...
Artificial Gravity Augmentation on the Moon and Mars
Extended visits to the moon and Mars will require a base on the surface. Exploration of small planetary neighbors will depend upon the development of a life support system that prevents...
Regenerative Life Support Technology Challenges for the Space Exploration Initiative
Regenerative life support systems have been identified as one of the critical enabling technologies for future human exploration of space. This discipline encompasses processes and subsystems...
LIAC: A Closed Ecosystem Research Facility
A preliminary design for a closed research facility capable of supporting multispecies and ecosystem level experiments is presented. This project will support NASA's Controlled Ecological...
An Integrated Human/Plant Metabolic Mass Balance Model
The design and development of Controlled Ecological Life Support Systems (CELSS) in support of future Lunar and Martian bases requires analytical models for evaluating human and biological...
A Systems Approach to Water Recycling Research
Because of the cost of Earth resupply, water recycling from wastewater is a critical enabling technology for long duration space missions. The need and the fact that water quality is not...
Internal Pressure in a Lunar Inflatable Structure
Design and construction of a structure on the Moon requires addressing a host of issues not encountered on Earth. A critical design factor is the internal atmospheric pressure necessary...
Linearisation and Offshore Fatigue Reliability
In determining the force effects due to wave action on offshore structures it is conventional to use an equivalent linearisation to convert wave velocities to forces via Morison's equation....
A Stochastic Model for Crack Initiation and Fatigue Life
A stochastic theory of high cycle fatigue life is based on a combination of the theory of diffusion in the presence of a stress field with activated state theory. The result is expressed...
Inspection Planning for Surface Fatigue Cracks
A reliability based method for planning of inspections to detect surface fatigue cracks is presented. Cracks are described as semi-elliptical surface cracks. The conditions governing fatigue...
Some Remarks on BK-Models for Fatigue Crack Growth
The choice of a model parameter for concentrating the entire uncertainties of a constant load amplitude fatigue crack growth process is shown to be sufficient when reproducing the first...
A Fatigue Reliability Model for Railway Bridges
A fatigue reliability model is described for safety evaluation of steel railway bridges. The model is a function of six independent random variables and can accommodate different types...
A Stochastic Approach to the Fatigue Reliability
In this paper, the stochastic approach, which combines the mixed boundary integral equation method (Lua et al (1992a)) with the First Order Reliability Method (FORM), is applied to study...
Fatigue Life Variability and Reliability Analysis of a Wind Turbine Blade
Wind turbines must withstand harsh environments that induce many stress cycles into their components. A numerical analysis package is used to illustrate the sobering variability in predicted...
Fatigue Strength of Welded Joints Under Broadband Loadings
Twelve welded high strength steel cruciform specimens were tested under stochastic loadings to determine the influence on fatigue life of the bandwidth of the loading process. Constant...
Low-Cycle Fatigue Prediction for Ramberg-Osgood Type Materials
The prediction of low-cycle fatigue crack growth is successfully made by an equation employing the J-integral range. This equation, originally proposed by Dowling and Begley, is analogous...
Fatigue/Fracture Reliability and Maintainability of Structural Systems: A Method of Analysis
Fatigue and fracture of structural components are the principal modes of failure for those structural systems that are dominated by tensile dynamic (oscillatory) loads. As the structure...
TLP Fatigue Due to Second-Order Springing
For offhsore oil production in water depths beyond 300-350 m, the tension leg platform (TLP) has become an increasingly popular design concept. The TLP is a floating structure with excess...
A Non-Gaussian Fatigue Model for Offshore Structures
Fatigue damage accumulation in members of offshore structures can be affected by various aspects of the non-Gaussian response stress time history induced by the nonlinear/non-Gaussian...
Risk Based Optimal Fatigue Testing
Optimal fatigue life testing of materials is considered. Based on minimization of the total expected costs of a mechanical component a strategy is suggested to determine the optimal stress...
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