Propeller hub center non-linear dynamic characteristic modeling method

Abstract

The invention discloses a propeller hub center non-linear dynamic characteristic modeling method, which belongs to helicopter theoretical modeling technology. The propeller hub center non-linear dynamic characteristic modeling method is characterized by comprising the following steps: establishing an engine body coordinate system, and describing the motion of an engine body and undercarriages; carrying out the balance computation of single undercarriage, and establishing force and position relationship between airplane wheels and a buffer; carrying out the balance computation of the engine body on the undercarriage; and determining the non-linear constraint force of an undercarriage system to the motion of the engine body in a time domain, and inertial load acted to the engine body, establishing an engine body motion equation on a fixed coordinate system by adopting a d'alembert's principle, and simultaneously establishing the balance equation of each undercarriage and the motion equations of the engine body on the undercarriage to obtain a propeller hub center non-linear dynamic characteristic equation of the engine body on the undercarriage. The invention can be applied to helicopter propeller hub center non-linear dynamic characteristic analysis and ground resonance modeling and analysis and can improve the accuracy of the propeller hub center non-linear dynamic characteristic analysis and the ground resonance stability analysis.

Description

technical field [0001] The invention belongs to the theoretical modeling technology of helicopters, and relates to a nonlinear dynamic characteristic modeling method of the hub center of a helicopter body on the landing gear for the analysis of the dynamic characteristics of the hub center of the helicopter body and the modeling and analysis of ground resonance. Background technique [0002] According to the requirements of the specification, before the ground resonance driving test of a helicopter with a new model or a major change in the landing gear system, the dynamic characteristic test and analysis of the center of the propeller hub must be carried out, so as to analyze the ground resonance and give a conclusion whether it can be driven. In the analysis of the dynamic characteristics of the helicopter hub center, engineering practice usually adopts a linear processing method based on small disturbances in the equilibrium position, assuming that the dynamic characteristi...

AI Technical Summary

Problems solved by technology

In the analysis of the dynamic characteristics of the helicopter hub center, engineering practice usually adopts a linear processing method based on small disturbances in the equilibrium position, assuming that the dynamic characteristics of the landing gear buffer and the wheel are linear, so that it is considered within a small amplitude range, From a microscopic point of view, when the actual amplitude does not exceed the range, the result is correct, but the correct conclusion cannot be drawn for the s

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