Logistic regression-based aircraft flutter analysis and QMU evaluation method

Abstract

The invention discloses a logistic regression-based aircraft flutter analysis and QMU evaluation method, and relates to a quantification technology of uncertainties and margins. The method comprises the following steps of 1) establishing a database of existing flight tests, namely whether the flight test suffers from flutter or not under a certain group of designed parameters, recording flutter as 1 and recording non-flutter as 0; 2) establishing a regression prediction model; 3) fitting a regression coefficient; 4) predicting the model; and 5) performing QMU evaluation. By omitting a complex finite element analysis process, high calculating efficiency and convenient operation are realized, and the method is applicable to the field where it is difficult to perform numerical value simulation on flutter and the like of a hypersonic thermal structure; the analysis result is evaluated by the QMU, and uncertainties of the flutter speed and flutter border are taken into consideration at the same time, so that security criterion for a flutter problem is high in credibility; and flutter probability of an aircraft under a certain designed variable condition can be predicted, so that the method can be used for assisting aircraft design.

Description

technical field [0001] The invention relates to margin and uncertainty quantification technology, in particular to an aircraft flutter analysis and QMU evaluation method based on logistic regression. Background technique [0002] Flutter is an aeroelastic instability phenomenon caused by the coupling of aerodynamic force, inertial force and elastic force. With the continuous increase of the speed of modern aircraft, the problem of flutter has become increasingly prominent, and the flutter analysis of aircraft structures has attracted extensive attention of researchers. In the field of hypersonic vehicles, the severe aerodynamic and thermal environment makes the flutter analysis face new challenges, and the flutter analysis of structures in thermal environments is an important issue facing hypersonic vehicles. [0003] The traditional aircraft flutter analysis method is to analyze by combining experiment and numerical simulation. However, for numerical simulation, on the on...

AI Technical Summary

Problems solved by technology

The QMU method takes the normal operation of the product as the research object, based on the fault physical model and margin design, and believes that in order for the system to achieve the required performance, it is necessary to reserve enough design margin for the system for the known potential failure modes, so as to Ensure that the system is absolutely reliable, but when calculating the performance margin M, it will be affected by various random and cognitive uncertainty factors. Once the combined value of these uncertainties is greater than the performance margin M, the product may malfunction or fail

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