Research On Concrete Fatigue Life Prediction Of Spiral Case Combined Structures Of Hydropower Station

The spiral case combined structure is not only the important support structure,but also the important through-flow structure of a hydropower station. It works in avery complicated load condition, suffers not only the static and the dynamic loadproduced by the turbine generator, but also the huge water pressure and fluctuatingpressure.In recent years, no matter the capacity of hydropower station or the singlecapacity of the generator becomes bigger and bigger. And the hydraulic head is higherand higher. The fatigue problem of the scroll combined structure caused by thefluctuating pressure and the vibration of hydraulic turbine appears more and moreimportant. This article adopts the method combined theoretical calculation and FEanalysis. A model to predict the fatigue life of concrete was proposed in which thedensity of the plastic strain energy was used as the damage parameter. Thecomparison with the experimental data verifies the applicability to different concretemarks. The specific content of this article includes the following several parts:(1) A model to predict the fatigue life of concrete was adopted which adopts thedensity of the plastic strain energy and the total strain energy as the damage parameter,and there’s a comparison with the experimental data which verifies the applicability todifferent concrete marks.(2) A three dimensional numerical model of the spiral case combined structurewas built, which mainly includes the floor and beam、turbine generator pier, scroll,draft tube and the surrounding concrete, etc. And there is a calculation of stress of thestructure in the normal condition.(3) Using the fatigue life prediction model of concrete mentioned above,combined with the result of the stress vs strain analysis, the fatigue life of the scrollcombined structure was predicted in this article.