Nonlinear dynamics modeling method of undercarriage wheel

Abstract

The invention relates to a nonlinear dynamic modeling method of an undercarriage wheel, belonging to a helicopter theoretical modeling technology. The nonlinear dynamics modeling method is characterized by comprising the following steps: carrying out vertical rigidity modeling, lateral rigidity modeling, course rigidity modeling and torsional rigidity modeling on the wheel according to structure parameters (inflation pressure, diameter and width) of the wheel, carrying out vertical damping modeling, lateral damping modeling, course damping modeling and torsional damping modeling on the wheel, solving an undermined coefficient in a model according to the static compression characteristic of the wheel and the dynamic rigidity damping test data by using a least square method, and acquiring an analytical expression capable of accurately simulating the nonlinear dynamic characteristic of the wheel in a time domain. The nonlinear dynamics modeling method disclosed by the invention can be used for dynamic characteristic analysis for the center of a propeller hub of a helicopter and ground resonance analysis, so that the accuracy of ground resonance stability analysis can be improved, great error caused to ground resonance analysis by linear processing is avoided and the helicopter weight cost caused by linear processing is avoided.

Description

technical field [0001] The invention belongs to the theoretical modeling technology of a helicopter, and relates to a nonlinear dynamics modeling method of a landing gear wheel used for the analysis of the dynamic characteristics of the hub center of the helicopter and the resonance analysis of the ground. Background technique [0002] In the analysis of helicopter ground resonance, 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 wheel are linear, so that it is considered in a small amplitude range. From a microscopic point of view, when the actual The results obtained when the amplitude does not exceed this range are correct, but correct conclusions cannot be drawn for situations beyond this range. In fact, the stiffness and damping of the landing gear wheels have nonlinear characteristics, and are sensitive to environmental changes, especial...

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Problems solved by technology

[0002] In the analysis of helicopter ground resonance, 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 wheel are linear, so that it is considered in a small amplitude range. From a microscopic point of view, when the actual The result obtained if the amplitude does not exceed this range is correct, but the correct conclusion cannot be drawn for the situation beyond this range

In fact, the stiffness and damping of the landing gear wheels have nonlinear characteristics, and are sensitive to environmental changes, especially when the helicopter has a large motion amplitude when the road surface is rough or the wind gusts are taking off and landing at sea, etc., the linearization process will Bring large errors to the ground resonance analysis

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