Turbine blade vibration reduction analysis optimization method

Abstract

The invention discloses a turbine blade vibration reduction analysis optimization method. The method comprises the steps of reading known parameters by a vibration response calculation program and calculating a maximum damping force and a maximum displacement in a local sliding state; calling ANSYS software to generate a finite element model at each determined frequency from a lower external excitation frequency limit; performing harmonic response vibration analysis on the model and calculating a vibration response of a system in the absence of damping; and calling a stiffness and damping calculation subprogram in a frequency domain analysis mode to calculate equivalent stiffness and equivalent damping. The vibration response of the system in the presence of the damping is calculated by calling the ANSYS software to obtain the amplitude value of a blade tip, and calculation is performed until an upper excitation frequency limit is reached. A turbine blade with a roof type damping fin is subjected to vibration characteristic analysis by applying a new dry friction model, and a result has a certain engineering guidance significance for design of a dry friction damper; and the method has a certain theoretical significance for calculation and analysis of the dry friction system.

Description

technical field [0001] The invention belongs to the technical field of aero-engines, and in particular relates to a vibration reduction analysis and optimization method of a turbine blade, which is a method research on the vibration reduction analysis of a turbine blade. Background technique [0002] Aeroengine blades often suffer from fatigue failure or fault fracture under large vibration stress, which has a great impact on the safe operation of aeroengines. Installing a vibration damper at the root of the blade can effectively solve the problem of excessive vibration of the blade. [0003] The friction between the blade and the damper belongs to dry friction. In the research of dry friction model, the commonly used friction models include global sliding model, local sliding model and global-local unified sliding model. The overall sliding model is a simplified model proposed for some special contact conditions. It is suitable for the size of the contact surface or the st...

AI Technical Summary

Problems solved by technology

The overall sliding model is a simplified model proposed for some special contact conditions. It is suitable for the size of the contact surface or the stress and strain field with a small normal load. However, this model is relatively simple and ideal, and cannot Accurately describe the real friction process

The local sliding model discretizes the contact area into multiple contact points, respectively considers the normal pressure and relative displacement of each contact point, and judges the motion state of each point, but it also greatly increases the calculation amount of the solution

The overall-local unified sliding model divides sliding into two states: viscous and complete sliding. The damping plate shows time-varying elastic characteristics and damping characteristics according to different situations. This model is closer to engineering reality and the response results obtained are more accurate. , but this model is still limited to flat plate dampers, further research is needed for complex multi-surface contact dampers

[0004] The domestic research on the model of the damper still focuses on the flat plate damper, and basically does not involve other more complicated models.

Images