COMPOSITES SCIENCE AND ENGINEERING ›› 2023, Vol. 0 ›› Issue (3): 11-17.DOI: 10.19936/j.cnki.2096-8000.20220428.031

• BASIC STUDY • Previous Articles     Next Articles

Prediction method of compressive strength after impact for fiber reinforced plastic composite based on the fractal dimension of impact damage

JIANG Wen1, FAN Hongxing2, YAO Weixing3,4, CHEN Fang5, MA Mingze4   

  1. 1. Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration, Nanjing Engineering Institute of Aircraft Systems, AVIC, Nanjing 211106, China;
    2. The Third Military Representative Office in Nanjing, the Military Representative Bereau of the Air Force Equipment Department in Shanghai, Nanjing 210016, China;
    3. Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle, NUAA, Nanjing 210016, China;
    4. State Key Laboratory of Mechanics and Control of Mechanical Structures, NUAA, Nanjing 210016, China;
    5. Institute of Structural Strength, Shanghai Aircraft Design and Research Institute, Shanghai 200120, China
  • Received:2022-02-25 Online:2023-03-28 Published:2023-04-28

Abstract: The bearing capacity of fiber reinforced plastic (FRP) composite is very sensitive to low-speed impact damage, so the prediction model of compression after impact (CAI) for FRP composite is vital to its engineering application. Therefore, the residual compressive strength tests of three different kinds of carbon fiber reinforced plastic (CFRP)/5284RTM/U3160 laminates under BVID state were carried out in this paper. The C-scan was used to obtain the impact damage morphologies of different CFRP laminates before compression test, and the impact damage morphologies were studied by the fractal dimension. The results show that the larger the fractal dimension of impact damage morphology, the lower the compression after impact. Based on this discovery, a prediction method of compressive strength after low-speed impact for fiber reinforced plastic composite based on the fractal dimension of impact damage was proposed. In this method, the impact damage morphology was equivalent to the basic fractal geometry (Sierpinski carpet), the non-bearing area of CFRP laminate could be obtained by the fractal theory. Then the residual compressive strength can be calculated by the normalized non-bearing area. The impact energy was not used as input parameter in this method, and the prediction results of the method were in good agreement with the experimental results. Therefore, the CAI prediction method proposed in this paper is convenient for engineering application.

Key words: fiber reinforced plastic composite, low-speed impact, residual compressive strength, fractal dimension

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