Fatigue Life Investigation for a Medium Scale Composite Hydrokinetic Turbine Blade


As the most important and expensive component of the hydrokinetic turbine system, the hydrokinetic turbine blade must achieve a long operating life of 10-20 years. In order to design a cost effective hydrokinetic turbine system for long term safe operating, investigation of fatigue life for the hydrokinetic turbine blade is required. In this paper, the fatigue life of a medium scale horizontal axis hydrokinetic turbine blade (1 m long) was estimated by using the rainflow cycle counting algorithm. The time series water velocity of Missouri river was analyzed based on the river discharge database over 90 years in station Hermann, Missouri. Different loading conditions according to varying water velocities are identified, calculated and evaluated. Critical zones of the blade are obtained by performing finite element analysis. Fatigue behavior of the blade is studied in these critical zones, and random load cases are weighted by rate-of-occurrence from stream patterns of the Missouri river. The allowable fatigue strengths are determined from MSU/DOE fatigue database for the S-N curve, and empirical coefficients are derived by modified Goodman diagram with the modified stress ratio and the required design life. Fatigue life of the hydrokinetic turbine blade indicates safe operation over 10 years.

Meeting Name

2012 SAMPE International Symposium and Exhibition


Mechanical and Aerospace Engineering

Keywords and Phrases

Cost Effective; Design Life; Empirical Coefficients; Fatigue Behavior; Fatigue Life Investigations; Fatigue Strength; Goodman Diagram; Horizontal Axis; Loading Condition; Missouri Rivers; Missouris; Operating Life; Rainflow Cycles; Random Load; River Discharge; S-N Curve; Safe Operation; Stream Patterns; Stress Ratio; Turbine Blade; Turbine Systems; Water Velocities

Document Type

Article - Conference proceedings

Document Version


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© 2012 Society for the Advancement of Material and Process Engineering (SAMPE), All rights reserved.

Publication Date

01 Jan 2012

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