Recursive convolution method for calculating coupling response and stability of rotorcraft body

Abstract

The invention provides a recursive convolution method for calculating coupling response and stability of a rotorcraft body. The recursive convolution method comprises the following steps: establishing a rotor body coupling dynamics analysis model; deriving a differential equation based on a rotor body coupling dynamics analysis model, linearizing a coefficient matrix of the differential equation in a 0 response manner, forming a linear equation, and reducing the order of the linear equation into a first-order standard equation form; obtaining a homogeneous solution and a forced response steady-state solution based on a first-order standard equation; calculating the state transition matrix of the time point of one circle based on the period integral of the state transition matrix; calculating the characteristic value of the state transition matrix, and judging the coupling stability of the rotor and the aircraft body based on the characteristic value; if the characteristic value of the state transition matrix is smaller than 1 and the rotor and body coupling response meets the convergence requirement, calculating a periodic value of a right-end excitation item, and a first-cycle convolution integral response; and on the basis of the response of the first cycle convolution integral, the state transition array and the periodicity of the excitation item, using a recursive convolution integral calculation method to calculate the response of the second cycle convolution integral.

Description

technical field [0001] The invention belongs to the technical field of helicopter dynamics analysis, in particular to a recursive convolution method for calculating the coupled response and stability of a rotor body. Background technique [0002] Estimating the rotor blade vibration load and body vibration response in the flight state of the helicopter, and the coupling stability of the rotor and the body are important parts of the helicopter dynamics design. Currently, in the analysis technology of the helicopter rotor blade vibration load and body vibration response, the rotor The vibration load of the blade is separated from the vibration response of the airframe, that is, the coupling is not considered, while the coupling stability is classified into the ground resonance and air resonance analysis techniques. The methods commonly used to predict rotor blade vibration loads include direct integration method, time finite element method, harmonic trim method, etc. [0003]...

AI Technical Summary

Problems solved by technology

[0005] The calculation scale of the harmonic trim method is relatively small, but the accuracy is low, and it cannot effectively include nonlinear effects

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