Strain monitoring method and device for forming process of three-dimensional woven composite material

A molding process and composite material technology, applied in measuring devices, using electrical devices, using optical devices, etc., can solve problems such as the inability to detect three-dimensional woven composite materials, and achieve the effect of improving molding quality

CN111366095AInactive Publication Date: 2020-07-03DALIAN UNIV OF TECH
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2020-07-03
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention provides a strain monitoring method and device for a forming process of a three-dimensional woven composite material. The method comprises the following steps: pre-embedding an FBG sensor into a weft yarn corresponding to a to-be-measured position, pulling the FBG sensor so that the FBG sensor can reciprocate along the extension direction of the weft yarn, and finally fixing a grating section of the FBG sensor to the to-be-measured position; starting spinning and yarn feeding to enable the warp yarn to wrap the weft yarn embedded with the FBG sensor so as to generate a three-dimensional woven prefabricated body, wherein the three-dimensional woven prefabricated body is connected with a temperature sensor; and putting the three-dimensional woven prefabricated body into a moldfor mold closing, and obtaining the strain change of the material according to the wavelength change of the FBG sensor and the temperature change of the three-dimensional woven prefabricated body. According to the invention, the strain field and the evolution process of the strain field in the curing molding process of the three-dimensional woven composite material structure can be monitored in real time.
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Description

technical field

[0001] The present invention relates to the technical field of material testing, in particular to a strain monitoring method and device during the forming process of a three-dimensional woven composite material. Background technique

[0002] In addition to high specific strength and high specific modulus, three-dimensional woven composite materials also have properties such as delamination resistance and impact resistance that traditional laminated composite materials lack. However, due to the large differences in the phase mechanics and thermodynamic properties of its components, the influence of various factors such as resin shrinkage and mold action, residual stress and strain are prone to occur during the molding process of composite materials. Therefore, it is necessary to monitor the strain field and its evolution during the molding process to evaluate the molding quality of composite products.

[0003] Chinese patent CN107367523 proposes a method for ...

Examples

Embodiment 1

[0039] like Figure 1-3 As shown, the working process of monitoring the strain during the forming process of 3D woven composites includes:

[0040](1) Select a number of standard optical fibers 2 with a diameter (125 μm), a grating segment 3 with a length of 4 mm, a FBG sensor 4 with a central wavelength of 1500 nm-1600 nm, and a fiber protection tube 1 with an outer diameter of 0.9 mm;

[0041] (2) Before the fiber bundle is spun, first determine the weft yarn 5 corresponding to the position to be measured, embed the FBG sensor 4 into the weft yarn so that it is wrapped by the fiber, and pull the FBG sensor so that the grating section corresponds to the position to be measured position, when the textile feeds the yarn, the FBG sensor is wrapped by the warp yarn 6 along with the weft yarn;

[0042] (3) Put the three-dimensional woven prefabricated body 7 into the mould, and paste the thermocouple sensor 8 on the prefabricated body, lead its wire out from the mould, along with...