Analysis Of Crack And Optimum Design For Scroll Case In Hydropower Station

The structure of Scroll Case is the important part of hydropower station, because of its complex structure and different stress character among engineerings, there is still some problems to be studied. Especially with the huge increasement of water head and power per suit, size of structure is huger, stress is more complex, so the optimum design and structure safety seem more important. This paper takes XiLongChi hydropower station as example, do the studies as foliowings:(1) The optimal design of reinforcement in scroll case structure. Applying ANSYS program, establish the whole 3D finite element model, analyze the stress, crack width and crack distribution of structure with different reinforcement ratio and arrangment, select the best reinforcement ratio and arrangment.(2) Based on the scroll case of XiLongChi hydropower station, apply the emulating method for the stress analysis of the preloading filling scroll case structure, this paper carry out the 3D finite element analysis with different preloading water head, study the relationship between the stress distribution of scroll case and reinforced concrete and the preloading water head, analyze the influence of preloading water head on the crack width and distribution, at last present reasonable preloading water head.(3 ) The influence of inductive crack on the structure of scroll case. The main purpose of setting inductive crack in the structure of scroll case is to controll the crack development, but it will influence the stiffness and stress of structure. This paper mainly study the stress, node displacement, crack width and crack distribution of structure of scroll cases with different inductive crack site and equivalent strength, and select the most effective project for inductive crack in the structure of scroll case.During the modeling and calculating, the simulation of structure is as accurate as possible to reflect the characteristic of the real engineering. As a result, some useful conclusions are drawn and can be referred to other similar projects.