Strength properties of flange structure of polyimide composite casing manufactured by RTM

• Published in: Hang kong cai liao xue bao Vol. 42; no. 5; pp. 119 - 126
• Main Authors: Lei, Shuai, Liu, Chang, Jia, Linjiang, Fu, Shanlong, Lin, Lizhi, Li, Yongrui, Li, Jun, Zhang, Daijun, Chen, Xiangbao
• Format: Journal Article
• Language: Chinese
• Published: Beijing Beijing Institute of Aeronautical Materials 01.10.2022; Journal of Aeronautical Materials
• Subjects: Carbon fibers; composite; Cyclic loads; Defects; Delamination; Fatigue cracks; Fatigue tests; Finite element method; Interlayers; Mathematical analysis; Optical microscopes; polyimide; rtm; strength; ultrasonic test
• ISSN: 1005-5053
• DOI: 10.11868/j.issn.1005-5053.2021.000219

According to the flanged structure of composite casing, a typical sample with laminated structure manufactured by RTM process was designed using T800 grade carbon fiber fabrics reinforced polyimide composite. The strength property under the uniaxial tension condition was simulated by finite element method, and the calculated fracture load was 21.7 kN. The maximum strain was appeared at the corner of flanged structure, indicated that the corner area of flanged structure was weak relatively. Ultrasonic C-scan and optical microscope methods were applied to analyze the internal quality of the corner area. The results show that the overall internal quality of the sample corner area is good without obvious delamination defects. However, some micro-pores enriched at near surface and the fill region are still visible. The measured average tensile fracture load is 19.81 kN, and that is very close to the calculated value. After cyclic loading with 25% of the fracture load for 24000 times, the residual tensile fracture