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A three-dimensional finite-element thermal/mechanical analytical technique for high-performance traveling wave tubesCurrent research in high-efficiency, high-performance traveling wave tubes (TWT's) has led to the development of novel thermal/ mechanical computer models for use with helical slow-wave structures. A three-dimensional, finite element computer model and analytical technique used to study the structural integrity and thermal operation of a high-efficiency, diamond-rod, K-band TWT designed for use in advanced space communications systems. This analysis focused on the slow-wave circuit in the radiofrequency section of the TWT, where an inherent localized heating problem existed and where failures were observed during earlier cold compression, or 'coining' fabrication technique that shows great potential for future TWT development efforts. For this analysis, a three-dimensional, finite element model was used along with MARC, a commercially available finite element code, to simulate the fabrication of a diamond-rod TWT. This analysis was conducted by using component and material specifications consistent with actual TWT fabrication and was verified against empirical data. The analysis is nonlinear owing to material plasticity introduced by the forming process and also to geometric nonlinearities presented by the component assembly configuration. The computer model was developed by using the high efficiency, K-band TWT design but is general enough to permit similar analyses to be performed on a wide variety of TWT designs and styles. The results of the TWT operating condition and structural failure mode analysis, as well as a comparison of analytical results to test data are presented.
Document ID
19910018122
Document Type
Technical Publication (TP)
Authors
Bartos, Karen F.
(NASA Lewis Research Center Cleveland, OH, United States)
Fite, E. Brian
(NASA Lewis Research Center Cleveland, OH, United States)
Shalkhauser, Kurt A.
(NASA Lewis Research Center Cleveland, OH, United States)
Sharp, G. Richard
(NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
September 6, 2013
Publication Date
June 1, 1991
Subject Category
Communications And Radar
Report/Patent Number
NAS 1.60:3081
E-5917
NASA-TP-3081
Accession Number
91N27436
Funding Number(s)
PROJECT: RTOP 650-60-20
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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