Identification method nonlinear characteristics of hinge-containing flexible structure

Abstract

The invention discloses an identification method for nonlinear characteristics of a hinge-containing flexible structure, which comprises the following steps of performing a dynamic test on the hinge-containing flexible structure, and simultaneously obtaining a structure displacement response x, a speed response v, an acceleration response a and an external excitation f; f = f according to formulaF=f-ma, calculating the restoring force F of the structure, wherein m is the mass of the hinge-containing flexible structure; utilizing the obtained three-dimensional data {x, v, F} to make a three-dimensional point set of the restoring force F about the displacement response x and the speed response v; adopting a natural neighborhood interpolation method to interpolate the three-dimensional pointset {x, v, F} and making a three-dimensional restoring force curved surface; when the speed is zero, extracting a displacement and restoring force relation curve, and determining a damping model through curve fitting; and when the displacement is zero, extracting a speed and restoring force relation curve, and determining a rigidity model through curve fitting. According to the method, the complex nonlinear model containing the hinge structure can be accurately identified, and the identification result is high in reliability.

Description

technical field [0001] The present invention relates, in particular, to a method for identifying nonlinear characteristics of hinged flexible structures. Background technique [0002] With the development of aerospace technology, aerospace structures tend to be large, flexible and high-precision. Due to the limitation of delivery technology and the requirement of large folding ratio, the spacecraft structure often contains a large number of hinges. For example, the components of the solar sail panel, extension arm and other structures are connected by hinges to realize the folding and unfolding functions. Due to the existence of gaps in the hinge structure, under the external excitation, the structure produces nonlinear phenomena such as collision and friction, resulting in the structure showing strong nonlinear characteristics, which affects the normal operation of the structure and related instruments. [0003] In the prior art, the nonlinear characteristic model of the h...

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Problems solved by technology

[0005] Purpose of the invention: The purpose of the invention is to provide an identification method for the nonlinear characteristics of hinged flexible structures that can solve the problem that the nonlinear characteristics of the structure cannot be accurately identified when the external excitation and dynamic response of the structure are known.

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