A Three-dimensional Elastic Stress Analysis For Turbine Blades

Turbine blade which bears a complex heat cycle load and mechanical loads, is a very important component of gas turbine. In order to ensure the stability and reliability of the gas turbine during its active time, turbine blades on the urgent need to do strength calculation to predict and control its life. Research on strength of a gas turbine rotor is done in this paper.Firstly, a commercial FEA software ANSYS is employed to construct a three-dimensional finite element modal of turbine blade. Compare several methods of constrains conditions apply, and select fit constrains condition. Then, the centrifugal load and thermal load are considered, a three-dimension elastic stress analysis is conducted. Obtain the distribution of stress under centrifugal load and thermal load: high stress area lie on root zone; von Mises stress of blade back side is higher than that of blade front side; the maximum value stress lie on the gas film hole which is in joint of blade and margin plate; the value of stress around gas film holes are higher than that of area without hole; the influence of hole is higher with radius reduce.And contact analysis for interference fit of rabbet and groove is conducted. The result shows that stress of rabbet and groove is high. Magnitude of interference of rabbet and groove are increase with radius reduce. The rabbet and groove will generate plastic yield when magnitude of interference up to one point. Ought to select magnitude of proper interference to guarantee enough friction, and made the influence of film holes most minimum.Through the turbine blades of stress theoretical study and analysis of the numerical calculation, sum up and improve the elastic analysis method of turbine rotor blades. This method of strong adaptability, it can calculate strength of blades of a lot of power plants such as the gas turbines, fans, steam turbine etc.