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...
Probabilistic Assessment of Composite Structures
Formal procedures are described which are used to computationally simulate the probabilistic behavior of composite structures. The computational simulation starts with the uncertainties...
Nonstationary Response Characteristics of Linear MDOF Systems
A new approximate methodology for nonstationary random vibration analysis of multi-degree-of-freedom linear systems is developed. Simple analytical expressions for the covariance response...
Random Initial Heterogeneity and Degradation in Brittle Materials
The question of implementation of the initial state of the material is addressed. The problem is tackled by assuming random initial values for a relevant variable, within a prespecified...
Leakage Characteristics of the St. Jude Heart Valve
The requirement for anticoagulant therapy in patients implanted with mechanical heart valve prostheses is well known. A plausible explanation for this requirement is that the leakage flow...
Flow Visualization Studies in the Novacor Left Ventricular Assist System
This paper discusses a series of experiments to visualize and measure flow fields in the Novacor left ventricular assist system (LVAS). The experiments utilize a multiple exposure, optical...
Computer Simulation of Granular Flows
Discrete-particle computer simulations using up to 15,000 identical spheres reproduce particle-scale information obtained from high-speed motion picture observations of disperse, collision-dominated...
Computer Simulation of Dry Layered Granular Flow Down an Incline Composed of Grains
Experiments show that gravity-driven dry granular flows are essentially layered for smooth spheres. This paper describes layer-to-layer interaction in the flow. Assuming two-dimensional...
Distributed Failure Analysis, Fallacies and Remedies
In the past, two distinctly different approaches - smeared and discrete failure descriptions have been utilised to capture failure mechanisms in solids and structures. These two approaches...
An Elastoviscoplastic Model for High Strength Concrete
An elastoviscoplastic model of overstress type is proposed for high-strength concrete in this study. With its viscosity parameters determined with experimental data from the split-Hopkinson-pressure-bar...
Stability of Systems of Rigid Bodies by Bounding Theorems
The stability of systems of systems of rigid bodies subjected to conservative and dissipative forces is investigated by considering the minimization of a work function subject to the kinematic...
Inverse Problems in Biomechanics
The FEM (Finite Element Method) is a powerful numerical technique in solving boundary value problems in Biomechanics, which are difficult to analyze by other closed form or numerical procedures...
Analysis of Two Lunar Oxygen Production Processes
Frequently, chemical engineers must evaluate processes, design systems, and size equipment based on a chemical or physical reaction without the benefit of laboratory data or previous industrial...
Assessing Lunar Resources with Remote Sensing
Four strategic architectures have been identified as part of the U.S. Space Exploration Initiative (SEI) to achieve U.S. goals with respect to the Moon. One of these architectures, space...
Modeling and Analysis of Doubly Curved Aerobrake Truss Structures
Recent studies have indicated that vehicles designed for a piloted mission to Mars may have their initial Earth Orbit mass reduced by nearly a factor of two if aerobraking is used rather...
Design Criteria for an Underground Lunar Mine
Underground excavation and construction techniques have been well developed terrestrially and provide an attractive option for lunar mining and habitat construction. The lunar mine, processing...
Optimum Design of Laminated Composites
The increased demand for high strength, light weight materials that function successfully in high temperature environments has caused the effective development of laminated composites...
Telerobotic Field Geologist: Preliminary Results of a Feasibility Study
We conducted three laboratory studies to explore the feasibility of developing a telerobot to perform planetary field geology. In all, 72 college students attempted to match each of 15...
Modular Robot Testbed
One approach to non-terrestrial construction involves the use of small, inexpensive, modular robots rather than expensive one-of-a-kind construction tools. The Modular Robots Testbed at...
The Virtual Mission: A Step-Wise Approach to Large Space Missions
The new Virtual Mission concept will provide NASA's Science Program with a powerful new, 'go-as-you-pay,' flexible, and resilient way of accomplishing its science observing program. The...
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