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Clayton, Daniel J. ; Potter, Donald L. ; Young, Larry W. ; Bixler, Nathan E. ; Lipinski, Ronald J. ; Bignell, John B. ; Jones, Christopher A. ; Rohe, Daniel P. ; Flores, Gregg J. ; Bartel, Timothy J. ; Gelbard, Fred G. ; Le, San L. ; Morrow, Charles W.
In the summer of 2020, the National Aeronautics and Space Administration (NASA) plans to launch a spacecraft as part of the Mars 2020 mission. One option for the rover on the proposed spacecraft uses a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) to provide continuous electrical and thermal power for the mission. An alternative option being considered is a set of solar panels for electrical power with up to 80 Light-Weight Radioisotope Heater Units (LWRHUs) for local component heating. Both the MMRTG and the LWRHUs use radioactive plutonium dioxide. NASA is preparing an Environmental Impact Statement (EIS) in accordance with the National Environmental Policy Act. The EIS will include information on the risks of mission accidents to the general public and on-site workers at the launch complex. This Nuclear Risk Assessment (NRA) addresses the responses of the MMRTG or LWRHU options to potential accident and abort conditions during the launch opportunity for the Mars 2020 mission and the associated consequences. This information provides the technical basis for the radiological risks of both options for the EIS.
Topics in Experimental Dynamic Substructuring - Proceedings of the 31st IMAC, A Conference on Structural Dynamics, 2013
Mayes, Randy L.; Rohe, Daniel P.
The transmission simulator method of experimental dynamic substructuring has the capability to couple substructures with continuous connections. A hardware example with continuous connections is presented in which the method is used to couple an experimental substructure with a finite element substructure to predict full system response. The predicted response is compared with frequency response functions measured on the full system hardware. The experimental substructure captures the motion of a component packed in foam. This is coupled to a finite element model of a cylindrical metal case which contains the foam and is attached through a flange to a plate and beam structure. © The Society for Experimental Mechanics, Inc. 2014.
Topics in Experimental Dynamic Substructuring - Proceedings of the 31st IMAC, A Conference on Structural Dynamics, 2013
Rohe, Daniel P. ; Mayes, R.L.
This paper presents an example of the transmission simulator method of experimental dynamic substructuring combining two substructures of the Substructures Focus Group's test bed, the Ampair 600 Wind Turbine. The two substructures of interest are the hub-and-blade assembly and the tower assembly that remains after the hub is removed. The hub-and-blade substructure was developed from elastic modes of a free-free test of the hub and blades, and rigid body modes were constructed from measured mass properties. Elastic and rigid body modes were extracted from experimental data for the tower substructure. A bladeless hub was attached to the tower to serve as the transmission simulator for this substructure. Modes up to the second bending mode of the blades and tower were extracted. Substructuring calculations were then performed using the transmission simulator method, and a model of the full test bed was derived. The combined model was compared to truth data from a test on the full turbine. © The Society for Experimental Mechanics, Inc. 2014.
Topics in Experimental Dynamic Substructuring - Proceedings of the 31st IMAC, A Conference on Structural Dynamics, 2013
Mayes, R.L. ; Rohe, Daniel P. ; Blecke, Jill B.
In previous work, a modal test of a large beam like structure on a vibration slip table was analytically constrained to fixed base providing estimates of the first three bending modes active in the direction of slip table motion. This work extends the frequency band of the method to extract the first ten fixed base modes of the test article. All ten fixed base modal frequencies are within two percent of the truth test fixed base modes. When compared to the truth test, the estimated damping of the lower modes has large error, but at higher frequencies the estimated damping converges on the truth value. © The Society for Experimental Mechanics, Inc. 2014.
Topics in Experimental Dynamic Substructuring - Proceedings of the 31st IMAC, A Conference on Structural Dynamics, 2013
Mayes, Randy L.; Rohe, Daniel P. ; Blecke, Jill B.
In previous work, a modal test of a large beam like structure on a vibration slip table was analytically constrained to fixed base providing estimates of the first three bending modes active in the direction of slip table motion. This work extends the frequency band of the method to extract the first ten fixed base modes of the test article. All ten fixed base modal frequencies are within two percent of the truth test fixed base modes. When compared to the truth test, the estimated damping of the lower modes has large error, but at higher frequencies the estimated damping converges on the truth value. © The Society for Experimental Mechanics, Inc. 2014.
Rohe, Daniel P. ; Blecke, Jill B. ; Schoenherr, Tyler F.
Rohe, Daniel P. ; Blecke, Jill B.
Mayes, R.L. ; Rohe, Daniel P. ; Blecke, Jill B. ; Schoenherr, Tyler F.
Mayes, R.L. ; Rohe, Daniel P.
Schoenherr, Tyler F. ; Rohe, Daniel P.
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