Distributed optical fiber computing method for wing strain field reconstruction based on modal superposition principle

Abstract

The invention relates to a distributed optical fiber computing method for wing strain field reconstruction based on a modal superposition principle, and belongs to the field of structural health monitoring. The method comprises the following steps that 1, based on measurement of fiber grating sensor wing structure strain, calculating the strain of the surface of a wing structure through fiber grating center wavelength offset; and 2, calculating a strain mode of the wing structure, and optimizing the fiber grating sensor network layout of the wing structure through the strain mode; 3, deducinga strain matrix corresponding to the position of the measurement point of the wing structure sensor and a conversion formula between strain matrixes of all points of the wing structure; and 4, for theproblem that the strain mode matrix is uncertain, adopting a regularization method to optimize the solution of the strain mode coordinates, and reducing the strain field reconstruction error. According to the method, response signals of fiber gratings with a small number of discrete points are collected, and a wing structure strain field is deduced and calculated through a formula.

Description

technical field [0001] The invention belongs to the field of structural health monitoring, and specifically proposes a distributed optical fiber calculation method for wing structure strain field reconstruction based on the principle of modal superposition, and specifically relates to the measurement of the strain of an optical fiber grating sensor, the principle of strain modal superposition, and optical fiber grating Sensor layout optimization, etc. Background technique [0002] In structural health monitoring, strain is a very important index. Strain reflects the strength of the structure, and the failure of the structure is usually related to the strain state. By analyzing the strain of the structure, the fatigue and cracks of the structure can also be monitored. When the structure is subjected to dynamic load, it is often damaged because the strain value on the structure exceeds the limit of the structure. Real-time monitoring of the strain of the structure can well av...

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Problems solved by technology

[0005] The common algorithm for strain field reconstruction is interpolation fitting method. The interpolation fitting method is simple to calculate, but the accuracy is not high, and for the sudden change of strain in the structure, if the key interpolation points are not obtained, the strain field reconstruction cannot be performed accurately.

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