Monitoring method of internal stress of spacecraft composite material structure in aging process

The invention provides a monitoring method of the internal stress of a spacecraft composite material structure in an aging process. The method includes following steps: step1, placing carbon fiber prepreg, a special optical fiber, carbon fiber prepreg, demolding cloth, and adhesive-absorbing felt on a molding mold of the spacecraft composite material structure in sequence, and performing integral sealing by employing a vacuum bag; step 2, performing curing by employing an autoclave process, performing demolding after cooling, and obtaining the spacecraft composite material structure implanted with the special optical fiber at the inner part; and step 3, placing the spacecraft composite material structure in a clean factory building, and performing aging treatment on the spacecraft composite material structure by employing a natural aging method. According to the method, based on a back Rayleigh scattering principle, the special optical fiber is implanted in the spacecraft composite material structure, the monitoring of the internal stress in the aging process is realized by employing an optical frequency domain reflection technology, the spatial resolution is high, the measuring precision is high, the repeatability is good, and basis is laid for improvement of the aging method of the spacecraft composite material structure and the improvement of the dimension stability.