Formed self-monitoring intelligent composite material and monitoring method thereof

Abstract

The invention discloses a formed self-monitoring intelligent composite material, and relates to the field of composite material manufacturing. The formed self-monitoring intelligent composite materialcomprises a composite material body and a sensing system; the composite material body is a woven composite material; the sensing system comprises a multifunctional sensing probe and a fiber bragg grating demodulator; the multifunctional sensing probe can monitor temperature and stress at the same time and comprises a temperature sensing component and a stress sensing component. The temperature sensing part is composed of a fiber bragg grating, a capillary tube and a sealant. The fiber bragg grating is packaged in the capillary tube through the sealant. The stress sensing part is an optical fiber embedded part. The multifunctional sensing probe is embedded into the braided composite material and is connected with the fiber bragg grating demodulator through the optical fiber. The structureof the formed self-monitoring intelligent composite material has the advantages of being small in size, light in weight, excellent in multiplexing capacity, high temperature resistance and electromagnetic interference resistance, reliable in monitoring result and small in influence on the mechanical property of the composite material.

Description

technical field [0001] The invention relates to the field of composite material manufacturing, in particular to a forming self-monitoring intelligent composite material based on embedded fiber grating and data processing and a monitoring method thereof. Background technique [0002] In recent years, fiber grating sensors have been extensively studied. Fiber Bragg grating sensors have the advantages of small size, light weight, and a large amount of monitoring, and have excellent multiplexing ability, high temperature resistance, and electromagnetic interference resistance, so they can be embedded in composite materials to monitor the molding process. [0003] The fiber grating sensor reflects the Bragg wavelength λ of the incident light by writing a diffraction grating that makes the refractive index of the fiber core undergo axial periodic modulation. B and light near it, the Bragg wavelength λ B Expressed as: [0004] lambda B =2n eff Λ [0005] Among them, n eff is...

AI Technical Summary

Problems solved by technology

Its microstructure is much more complex than that of composite materials stacked by unidirectional prepregs, and it will squeeze the embedded fiber grating under high pressure, resulting in reduced reflectivity, unrecognizable signals and even destruction of the fiber grating

In addition, the thermocompression molding process of thermoplastic braided composites requires high pressures, 2 MPa for polyetherimide matrix composites, which may lead to failure of embedded sensors using fragile ceramic capillaries or silica capillaries

High temperature, micro-braided structure and high pressure all make the molding process of thermoplastic braided composites difficult to monitor

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