A5003380352- Ultrasonics and Acoustic Wave Propagation
- Structural Health Monitoring Techniques
- Additive Manufacturing and 3D Printing Technologies
- Spacecraft and Cryogenic Technologies
- Geophysical Methods and Applications
- Additive Manufacturing Materials and Processes
- Non-Destructive Testing Techniques
- Spacecraft Design and Technology
- Rocket and propulsion systems research
- Structural Response to Dynamic Loads
- High Entropy Alloys Studies
- Acoustic Wave Phenomena Research
- Composite Material Mechanics
- Heat Transfer and Numerical Methods
- Injection Molding Process and Properties
- Planetary Science and Exploration
- Fault Detection and Control Systems
- Textile materials and evaluations
- Space Exploration and Technology
- Welding Techniques and Residual Stresses
- Scientific Measurement and Uncertainty Evaluation
- Material Properties and Applications
- Technology Assessment and Management
- Probabilistic and Robust Engineering Design
- Nuclear Engineering Thermal-Hydraulics
Ames Research Center
2010-2024
Stinger Ghaffarian Technologies (United States)
2011-2019

 Safety of the next-generation space flight vehicles requires development an in-flight Failure Detection and Prognostic (FD&P) system. Development such system is challenging task that involves analysis many hard hitting engineering problems across board. In this paper we report progress in FD&P for re-contact fault between upper stage nozzle inter-stage caused by first separation failure. A high-fidelity models analytical estimations are applied to analyze following sequence...
A water recycling system (WRS) deployed at NASA Ames Research Center's Sustainability Base (an energy efficient office building that integrates some novel technologies developed for space applications) will serve as a testbed long duration testing of next generation spacecraft systems future human spaceflight missions. This cleans graywater (waste collected from sinks and showers) recycles it into clean water. Like all engineered systems, the WRS is prone to standard degradation due regular...
Results of modeling the wave propagation, impact, and damage detection in a sandwich honeycomb plate using piezoelectric actuator/sensor scheme are reported. A finite element model panel that reproduces accurately experimental setup takes into account main characteristic features real composite panel, impactor, lead zirconate titanate actuator, sensors is developed. The impact simulated to obtain with parameters close those observed experiment. Both simulations experiment, voltage signal...
Abstract We consider an atomistic model of thermal welding at the polymer‐polymer interface a polyetherimide/polycarbonate blend, motivated by applications to 3D manufacturing in space. follow diffusion semiflexible chains and analyze strengthening samples as function time t w simulating strain–stress shear viscosity curves. The scales for initial wetting, fast slow diffusion, are revealed. It is shown that each component polymer blend has its own characteristic interface. Analysis...
High-Fidelity Model of the sandwich composite structure with real geometry is reported. The model includes two facesheets, honeycomb core, piezoelectric actuator/sensors, adhesive layers, and impactor. novel feature that it modeling impact wave propagation in before after impact. Results propagation, impact, damage detection plates using actuator/sensor scheme are results simulations compared experimental results. It shown suitable for analysis physics failure due to testing structural...
This presentation deals with the mathematical modeling of composite microstructures for uncertainty quantification structural parameters. Multiple designs unidirectional fiber reinforced materials arbitrary ply orientations are investigated. We consider a homogenization approach from microscopic to macroscopic scales prediction mechanical properties composites. An assessment effective modulus consisting an elastic matrix fibers as functions phase volume fractions and constituents is...
We report on the development of a hierarchy models cryogenic two-phase flow motivated by NASA plans to develop and maturate technology propellant loading ground in space. The solution this problem requires that are fast accurate enough identify conditions, detect faults, propose optimal recovery strategy. described presentation is ranging from homogeneous moving- front approximation separated non-equilibrium flow. compare model predictions with experimental data discuss possible application...
Wave propagation is investigated in sandwich composite panels using analytical approach for layered materials, Mindlin plate theory and finite element modeling the context of developing an on-board structural health monitoring system. It shown that theoretical results are agreement with numerical simulations experimental results.
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Covers advancements in spacecraft and tactical strategic missile systems, including subsystem design application, mission analysis, materials structures, developments space sciences, processing manufacturing, operations, applications of technologies to other fields.

 This paper reports on analytical as well computer simulation of waves propagating in sandwich-type composite structures. Sandwich-type composites are being studied for use NASA’s new heavy lift launch vehicle, and flaw detection is crucial safety failure prognostics. Theoretical analysis, numerical modeling, needed benchmarking available technologies structural health monitoring (SHM) sensors sensor systems. activity important answering the basic question what minimum size can be...
Results from the NASA Low Cost Upper Stage Program (LCUSP) showed that there were very large residual stresses in thrust cell assemblies produced by additive manufacturing. To address concerns regarding such stresses, models of manufacturing process developed under Rapid Analysis and Manufacturing Propulsion Technology (RAMPT) Program. Alloy 625 was chosen as first material to be modeled because a existing mechanical thermophysical database it used during LCUSP has applicability other engine...
A moving-boundary model of two-phase (TP) flow in a cross-country cryogenic fuel supply line has been developed. It is based on time-dependent one-dimensional ordinary differential equations that describe mass and energy conservation the flowing cryogen exchanges heat with tubes' walls. The momentum taken into consideration by relating pressure drop across boundaries control volumes (CVs) corresponding inlet outlet rates through these volumes. With relatively small computational effort...
In a modern world, importance of computer modeling for solving complex engineering problems cannot be overstated. However, in number critical computational models provide unique answer and so further physical analytical insight is required to guide simulations. Such an becomes even more valuable when off-nominal regimes operation have considered. To deal with complexity the process at interface multiple systems new discipline emerging – operational physics missions. This combines old-good...
Covers advancements in spacecraft and tactical strategic missile systems, including subsystem design application, mission analysis, materials structures, developments space sciences, processing manufacturing, operations, applications of technologies to other fields.