A Space Station Simulation: EXEMSI '92 A Study on Confinement and Isolation of a Mixed Crew of Four during 60 Days
Manned spaceflight is entering a new era. The next period will be characterized by long duration stays in space and heterogenous crews. EXEMSI '92 was an attempt to study the human-related...
Modeling of Interaction of Small Particulates in Earth Orbit
The hazards posed by small debris is an area of increasing concern for all space systems. Depending on the size and relative encounter velocity of small particulates, there are a variety...
Integrated Spacecraft Environments Model (ISEM)
Capabilities of the ISEM code are presented that can aid in the understanding of the complex interactions between a space system and the ambient environment. The development of ISEM has...
Energy Analysis of High Temperature Lunar Manufacturing Processes
This paper presents an energy analysis methodology to optimize the power system requirements for high temperature manufacturing processes on the moon. Power requirement and power system's...
The Levitation of Lunar Dust Via Electrostatic Forces
Apollo and Surveyor photographs revealed an unexpected lunar phenomenon that has come to be known as the 'horizon glow'. During lunar sunrise and sunset, a line of light was visible above...
Efficient Path Planning Strategies for Unmanned Rover Vehicles
Path planning strategies are studied using an optimization model. Four main sub-models are discussed that contribute to the computing of minimum energy vehicle path planning. These are:...
Load Duration Effects in an 85-Year-Old Timber Structure
Duration of load (DOL) effects are assessed in 85-year-old heavy timber trusses using five common DOL models. These models are based on the idea of static damage accumulation. Material...
Seismic Analysis of Bridges: Simplified or Refined Approach
This paper discusses the differences of seismic responses of bridges among various analysis methods and approaches....
Bridge Rail Impact Forcing Functions
Bridge rails are designed according to AASHTO standards with a static 10-kip (44.5 kN) lateral load. The computer programs BARRIER VII and COSMOS are used to determine the deflections...
Human Error Models for Structural Reliability
This paper presents models for human errors to be used along with reliability analyses. The models account for the occurrence of errors, their magnitude, and the detection of the errors....
Strut-Tie Model Design of Disturbed Regions in Concrete Structures
The design of disturbed (highly non-linear behavior) regions in concrete structures is illustrated using strut-tie approach. The use of this approach assisted with interactive computer...
A New Laboratory for Teaching Structural Engineering
A new, practical, computer-assisted laboratory, 'AN/EX,' has been developed for teaching structural engineering. Specifically, AN/EX has been developed to encourage cross-verification...
Discontinuous Control of Seismic-Excited Nonlinear and Hysteretic Structures
Based on the theory of variable structure system (VSS) or sliding mode control (SMC), discontinuous control methods are presented for application to seismic-excited nonlinear civil engineering...
Hurricane Windspeeds at Inland Locations
A critical review of the windfield and filling models used in the hurricane simulation procedure of Batts et al. [1980] clearly indicates that the hurricane windspeeds they obtained for...
Numerical Simulation of Site Effects
Numerical simulations have proved to be very powerful tool in the analysis and study of site effects. Numerical models may be used (i) to study the pattern of shaking during a particular...
Modelling of Extended Endplate Bolted Connections
A methodology based on finite element modelling is examined to study the behaviour of extended endplate bolted connections. ANSYS (Rev. 4.4), a large scale finite element program is used...
An Overview of Shotcrete Usage on the SSC
Shotcrete has been widely used on the Superconducting Super Collider for initial support of tunnel excavations in both the strong and weak rock formations encountered. Different types...
Wind Deflection Probability Analysis
A statistical analysis is performed which analyses the probability of various magnitudes of deflections of a cable-stayed roof occurring due to wind uplift. Extensive wind analyses were...
Synthetic Wind for Investigations in Time-Domain
Buffeting investigations of large bridges carried out in time-domain permit modelling of the non-linearity of the system and wind force. Correct simulation of the natural wind plays a...
Structural Analysis of Pavements: State-of-the-Art
This paper presents the state of the art of the structural analysis of pavements, using high-speed computers. The numerical models include layered analysis and finite-element and finite-difference...
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