A Flutter Analysis Method for Functionally Gradient Variable Thickness Blade Model

Abstract

The invention discloses a flutter analysis method for a functional gradient variable thickness blade model, specifically comprising the following steps: constructing a functional gradient variable thickness blade model, extracting basic parameters of NURBS; obtaining new control points and The node vector information is used to construct the interpolation basis function for flutter analysis; the above-mentioned basis function is used to describe the flutter displacement variable of the blade with variable thickness, and its energy is established through the first-order piston theory, refined plate theory and corresponding boundary conditions Functional function; calculate the stiffness matrix and mass matrix of a single parameter element; based on this, the overall stiffness and mass matrix are formed cyclically, and the flutter characteristic results of blades with variable thickness are obtained. The invention utilizes the isogeometric method, the combination of the refined plate theory and the first-order piston theory, and uses fewer control points to describe complex geometric shapes. While ensuring the geometric accuracy of variable-thickness blades, it saves calculation costs and improves analysis efficiency. efficiency.

Description

technical field [0001] The invention belongs to the field of structural dynamics, and in particular relates to a flutter analysis method of a function gradient variable thickness blade model. Background technique [0002] Blades are one of the main components of turbomachinery and are widely used in various aerospace, shipbuilding and other industrial fields. Due to the influence of high-speed airflow, the blade will vibrate under certain circumstances. The occurrence of flutter will cause serious damage to the blades and even the entire turbomachinery. Therefore, an in-depth study of the flutter problem of the blade model has important theoretical and practical guiding significance for the early design of the blade and the avoidance of flutter in the later stage. [0003] In recent years, most scholars have studied the flutter problem of blade models, usually using slender beam models, plate models and thin shell models. However, the slender beam model ignores the force ...

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Problems solved by technology

However, the slender beam model ignores the force in the y direction and is only applicable to the case of a large aspect ratio; although the plate model and the shell model can be applied to the case of a small aspect ratio, for the actual situation, the blade model is often It is not a regular beam-plate shell. Due to the limitation of the method, scholars often do not consider this when studying the flutter of the blade model, so it is very necessary to consider the flutter problem of the blade model with variable thickness

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