Boundary Condition Identification of Turbine Blades for Modal Analysis Using Finite Element Model Updating

Because of importance and great role of turbine in advanced industry, especially power plant industry, suitable design of turbine blades can decrease cost and increaselife of turbines. Also since influence of appropriate design of turbine blades on efficiency of turbine, design of blades is complex and blades are considered as an expensive part of turbine. Vibratory design of turbine blades must be considered because of periodic loading of turbine blades. For identification of boundary condition ofturbine blades one can use a mathematical model of turbine blades. By using a mathematical model and applying its boundary condition parameters, one canutilize modal parameters of structure with various support parameters. This model may be used to predict responses to service loads, assess structural design integrity, designmodifications or system fault diagnosis. It has been found that it is difficult to estimate the values of the boundary stiffness based on intuition or engineering judgments. However, after creating an initial FE model, the boundary parameter should be identified based on experimental modal data obtained from modal tests so that the FE model may be used with confidence for further analysis. Adjusting of incorrect values of parameters in finite element model and identification of its parameter is a process which performs in model updating. Updating uses an initial FE model and experimental modal data of the structural components to modify physical parameters of the initial FE model, and a number of approaches have been developed to perform this task.

کلیدواژه ها:

Modal Analysis ، Turbine Blade ، Finite Element Model ، Model Updating