Modeling method of grid model of aircraft flutter analysis

Abstract

For overcoming the problem that the prior art cannot effectively express complex flutter models under influences of aerodynamic force and intensity changes, the invention provides a modeling method ofa grid model of aircraft flutter analysis. According to the method, a plurality of grid points are selected in aircraft airframe shafting, The complex flutter grid model is expressed under the influences of the aerodynamic force and intensity changes such as different flight speeds, atmospheric densities, airflow environments, temperatures according to an airframe shafting decomposition method, sensor installation and data and image recording requirements are presented according to requirements of establishing the model, data are acquired through effective flutter flight testing, excitation functions are obtained through airflow sensor measurement values, given functions are used for approximation and equivalent description on vibration variables, structure coefficient functions of threeaxial vibration equations of airframe shafting coordinate grid points are determined according to structure identification and parameter identification methods, and the technical problem that the prior art cannot effectively express the complex flutter models under the influences of the aerodynamic force and intensity changes is solved.

Description

technical field [0001] The invention relates to a ground comprehensive test method for flight safety of aircraft such as civil aircraft, fighter jets, and unmanned aerial vehicles, in particular to an aircraft flutter analysis grid model modeling method, and belongs to the field of aerospace and information technology. Background technique [0002] Flutter is a large-amplitude vibration phenomenon that occurs when an elastic structure is coupled by aerodynamic, elastic, and inertial forces in a uniform airflow. For aircraft, vibration occurs after an uncertain disturbance in flight. At this time, due to the effect of the airflow, the elastic structure of the aircraft such as the wing, empennage or control surface will generate additional aerodynamic force; as an exciting force, the additional aerodynamic force will aggravate the vibration of the structure. At the same time, the damping force of the air on the aircraft structure tries to weaken the vibration; when flying at ...

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Problems solved by technology

[0006] In order to overcome the problem that the prior art cannot effectively express complex flutter models under the influence of aerodynamic force and strength changes, the present invention provides a method for modeling aircraft flutter analysis grid models. Under the influence of different flight speeds, atmospheric densities, airflow environments, and different temperatures and other aerodynamic and strength changes, the complex flutter grid model is expressed according to the decomposition method of the body shaft system. According to the requirements for establishing the model, the installation of sensors and data, Image recording requirements, obtain data through effective flutter flight test, obtain excitation function through airflow sensor measurement value, use given function to approximate and equivalently describe vibration variables, and determine airframe axis coordinate grid according to structure identification and parameter identification methods The structural coefficient function of the three axial vibration equations at the point solves the technical problem that the existing technology cannot effectively express the complex flutter model under the influence of aerodynamic force and strength changes

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