Continuous structure dynamic load interval identification method

Abstract

The invention discloses a continuous structure dynamic load interval identification method, which aims at a continuous structure with interval uncertainty and utilizes limited displacement response and sample information to identify an interval boundary of a dynamic load. The method comprises the following steps: firstly, establishing a finite element model with a continuous structure, convertingthe finite element model into a state space, and randomly generating a plurality of sample points in a sampling space by adopting a Latin hypercube sampling method; at each sample point, on the basisof minimum variance unbiased estimation, achieving one-step delay load identification by utilizing a structure state estimation value and structure observation information, and further achieving stateestimation and further updating of a state estimation covariance matrix under a Kalman filtering framework; and at each sampling moment, based on the uncertain variable uncertain dynamic load sampleset, establishing a random forest proxy model of the load on the interval convex model, and realizing identification of the load interval boundary by searching the maximum value of the proxy model onthe interval uncertain domain.

Description

technical field [0001] The invention relates to the field of aerospace, in particular to a dynamic load interval identification method for a continuous structure. Background technique [0002] In engineering practice, in order to accurately grasp the vibration state of the aircraft, it is often necessary to obtain the external excitation information acting on the structure. However, acquiring load information directly through force sensors is often not feasible due to the high cost and difficulty of installation. In recent years, more and more attention has been paid to the inverse load identification method based on structural vibration response data (displacement, acceleration, strain, etc.) combined with structural system characteristics (mass, stiffness, and mode). Different from directly solving the structural dynamics forward problem of the quadratic differential equation, the inversion process of load identification is often accompanied by many ill-posed problems, re...

AI Technical Summary

Problems solved by technology

The current interval uncertainty propagation analysis methods mainly include vertex combination method, perturbation method, and method based on Taylor series expansion, but these methods are suitable for relatively simple problems such as monotone problems, small uncertainty problems and linear problems.

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