The role of stator vanes is to straighten the air flow on each stage of axial compressors. They are so subject to dynamically fluctuating high pressure loads. Furthermore, monobloc clustered designs have been developed to facilitate the manufacturing process and reduce costs, but they result in the loss of cyclic symmetry properties and very low structural damping. This makes it more difficult to predict vibratory behavior, when taking high modal density and extreme sensitivity to mistuning into account, end even more essential to ensure structural strength in the context of fatigue. In most cases, mistuning due to geometrical and material tolerances is unknown. Here, an analytical method has been developed to predict the average vibratory response of a clustered stator vane in which the Young modulus of certain blades is associated with a random variable mimicking the mistuning effect. This method is based on a linear approximation of the evolution of eigenfrequencies as a function of a random variables, as eigenvectors are almost constant, and a dynamic flexibility matrix reconstruction strategy. This method was tested on a simplified stator vane model based on a 2D Euler-Bernoulli beam lattice. The results are quite accurate when pressure is uniformly distributed on the "blades" and when the ferrule to blade stiffness ratio is high. This approach provides a simple model that can be used in the first stages of design as it allows fast simulation with a large number of random variables and with good approximation of the average vibratory response.
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