Some Interesting Applications of Probabilistic Techiques in Structural Dynamic Analysis of Rocket Engines
- Brown, Andrew M.
- June 5, 2014.
- Physical Description:
- 1 electronic document
- Restrictions on Access:
- Unclassified, Unlimited, Publicly available.
- Numerical and Analytical methods developed to determine damage accumulation in specific engine components when speed variation included. Dither Life Ratio shown to be well over factor of 2 for specific example. SteadyState assumption shown to be accurate for most turbopump cases, allowing rapid calculation of DLR. If hotfire speed data unknown, Monte Carlo method developed that uses speed statistics for similar engines. Application of techniques allow analyst to reduce both uncertainty and excess conservatism. High values of DLR could allow previously unacceptable part to pass HCF criteria without redesign. Given benefit and ease of implementation, recommend that any finite life turbomachine component analysis adopt these techniques. Probability Values calculated, compared, and evaluated for several industryproposed methods for combining random and harmonic loads. Two new excel macros written to calculate combined load for any specific probability level. Closed form Curve fits generated for widely used 3(sigma) and 2(sigma) probability levels. For design of lightweight aerospace components, obtaining accurate, reproducible, statistically meaningful answer critical.
- NASA Technical Reports Server (NTRS) Collection.
- Document ID: 20140011713., M14-3687., Presentation to faculty at the Universite de Liege; 5 Jun. 2014; Liege; Belgium., and Presentation to faculty at the Royal Institute of Technology ; 5 Jun. 2014; Stockholm; Sweden.
- No Copyright.
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