Modeling method for reduced-order model of large flexible structure based on dynamic response recognition

Abstract

The invention discloses a modeling method for a reduced-order model of a large flexible structure based on dynamic response recognition, which comprises the following steps of: discretizing a nonlinear structure dynamic equation at equal time intervals to form a generalized coordinate discrete sequence, then carrying out discrete Fourier transform on the generalized coordinate discrete sequence to form a frequency domain transform sequence, and finally, carrying out dynamic response recognition on the frequency domain transform sequence; a part of items of a motion equation are exchanged in sequence to form a linear equation set, a mode of multiplying a modal combination by a proportionality coefficient is utilized to construct a test load, the test load is loaded on a structure to calculate dynamic response, dynamic response data are advanced, then a least square solution of the equation set is solved, a nonlinear rigidity coefficient can be given, and a nonlinear structure reduced-order model is established. Compared with a traditional large flexible structure reduced-order model based on statics response data recognition, the large flexible structure reduced-order model based on dynamic response recognition constructed by the method has the advantages that the nonlinear rigidity coefficient is recognized by utilizing a structural dynamic response data sample, and more accurate structural dynamic characteristic information can be provided.

Description

technical field [0001] The invention relates to the technical field, in particular to a method for modeling a reduced-order model of a large flexible structure based on dynamic response identification. Background technique [0002] The requirements of modern aircraft design for flight performance are constantly increasing. Large flexible aircraft represented by high-altitude long-endurance UAVs and flying-wing UAVs have gradually become the research focus of major aviation countries since the 1990s. This type of aircraft can continuously perform tasks such as military reconnaissance, civilian scientific exploration, and communication relay in a more flexible manner. It has a flight altitude and endurance far exceeding that of traditional aircraft, and has broad application prospects. Due to its flight performance requirements, large flexible aircraft usually use a larger wing aspect ratio to increase the lift-to-drag ratio, and at the same time increase the proportion of com...

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Problems solved by technology

[0005] In view of this, the present invention provides a reduced-order model modeling method for large flexible structures based on dynamic response identification, which is used to overcome the problem that only static response data are used as identification samples in the existing reduced-order model modeling of large flexible structures. Insufficiency that leads to the inability to accurately capture the structural dynamics characteristics, establish a structural reduced-order model suitable for deformation analysis of large flexible structures

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