Study on the size effect of curing deformation and maximum stress difference on composite U-shaped members

doi:10.19936/j.cnki.2096-8000.20260528.004

Abstract

Abstract: The curing deformation and stress difference generated during the curing and molding of composite materials significantly affect the forming accuracy, structural assembly and service life of components, especially in large-sized, irregular U-shaped structures widely used in the aerospace field. This study is the first to conduct a systematic investigation on the curing deformation and stress difference of large-sized, irregular U-shaped structures. It analyzed and compared the temperature, curing degree, curing deformation and stress distribution characteristics of different layups, revealing the law of size effect and the nonlinear variation of the maximum stress difference. The research found that the curing degree field and the temperature field have similarities. In the early stage, the temperature and curing degree of the inner and outer layers increase rapidly, while in the later stage, the middle layer will complete the overtaking. The stress field in the thickness direction shows an interlayer gradient effect, with the middle layer maintaining a uniform distribution characteristic, while the inner and outer boundary layers form a non-uniform distribution pattern. The curing deformation evolution of thin-walled, irregular U-shaped structures conforms to the law of size effect. The maximum stress difference decreases with the increase of the external dimensions. During the thickness control process, there is a critical point of the minimum value. After exceeding this point, the maximum stress difference gradually increases, and this critical thickness value increases with the increase of the component’s external dimensions.

Key words: composites, cure deformation, maximum stress difference, size effect, degree of cure, critical thickness

CLC Number:

TB332

LIU Yang, ZHAO Honghua, BAI Ruixiang, HUANG Yuqi, JIA Zhi, JIAN Kai. Study on the size effect of curing deformation and maximum stress difference on composite U-shaped members[J]. COMPOSITES SCIENCE AND ENGINEERING, 2026, 0(5): 23-33.

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