This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Fatigue Analysis Methodology for Predicting Engine Valve Life
Technical Paper
2003-01-0726
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Using FEM (Finite Element Method) and other analytical approaches, a systematic methodology was developed to predict an engine valve's fatigue life. In this study, a steel (SAE 21-2N) exhaust valve on an engine with a type 2 valve train configuration was used as a test case. Temperature and stress/strain responses of each major event phase of the engine cycle were analytically simulated. CFD models were developed to simulate the exhaust gas flow to generate boundary conditions for a thermal model of the valve.
FEM simulations accounted for thermal loads, temperature dependent material properties, thermal stresses, closing impact stresses and combustion load stresses. An estimated fatigue life was calculated using Miner's rule of damage accumulation in conjunction with the Modified Goodman approach for fluctuating stresses.
Predicted life results correlated very well with empirical tests. In one scenario for an unstable valve train, early valve failure was predicted at 500 hours of engine testing that correlated to actual test failures from 460-500 hours. In other test scenarios, the methodology was able to accurately predict valve survivability to 600 hours of engine testing.
Recommended Content
Authors
Topic
Citation
Roth, G., "Fatigue Analysis Methodology for Predicting Engine Valve Life," SAE Technical Paper 2003-01-0726, 2003, https://doi.org/10.4271/2003-01-0726.Also In
References
- Kays, W.M. Crawford, M.E. Convective Heat and Mass Transfer 3rd McGraw-Hill New York 1993 316
- Shigley, J. Edward Mitchel, Larry D. Mechanical Engineering Design 4th McGraw-Hill New York 1983 308 311