• CN: 11-2187/TH
  • ISSN: 0577-6686

Journal of Mechanical Engineering ›› 2023, Vol. 59 ›› Issue (13): 325-342.doi: 10.3901/JME.2023.13.325

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Mechanical Behavior of Material Removal and Predictive Force Model for CFRP Grinding Using Nano Reinforced Biological Lubricant

GAO Teng1, LI Changhe1, ZHANG Yanbin1, YANG Min1, CAO Huajun2, WANG Dazhong3, LIU Xin4, ZHOU Zongming5, LIU Bo6   

  1. 1. School of Mechanical and Automotive Engineering, Qingdao University of Technology, Qingdao 266520;
    2. College of Mechanical and Vehicle Engineering, Chongqing University, Chongqing 400044;
    3. School of Air Transportation, Shanghai University of Engineering Science, Shanghai 201620;
    4. School of Mechanical Engineering, Dalian University of Technology, Dalian 116024;
    5. Hanergy(Qingdao) Lubrication Technology Co., Ltd., Qingdao 266200;
    6. Sichuan Future Aerospace Industry LLC., Shifang 618400
  • Received:2022-07-15 Revised:2023-02-05 Online:2023-07-05 Published:2023-08-15

Abstract: Carbon fiber reinforced polymers (CFRP) have become the preferred material for weight reduction of aerospace equipment due to their high specific strength and stiffness, and their ability to integrate design and manufacture of material structure and performance. Precision grinding is a necessary machining method to ensure assembly tolerance and accuracy after CFRP forming. Cutting fluid solves the problems of cooling lubrication and chip removal under the strong mechanical-thermal coupling of grinding interface. However, CFRP is easy to absorb moisture and expand, resulting in the reduction of mechanical properties, which limits the application of flood lubrication. Dry cutting is prone to cause surface integrity deterioration and dust pollution. Quasi-dry cutting is an inevitable choice to use a minute quantity of biological lubricant to atomize and infiltrate the cutting area. However, the mechanical behavior of material removal in precision surface grinding of heterogeneous and anisotropic CFRP remains unclear. Based on the above, a CFRP grinding method using nano-enhanced bio-lubricant minimum quantity lubrication is proposed. Firstly, the geometric kinematics of grains in the grinding zone is analyzed, and the grinding interference state of random grains on random fibers of heterogeneous CFRP is studied. Secondly, the contact mechanical behavior and the removal mechanism of grains on fiber cross-section are revealed. The bending and torsion failure of unilaterally restrained fibers and the interfacial phase debonding are analyzed. The average stress of fiber fracture during fiber bundle removal is determined by analyzing the mechanical behavior of multi-fiber bulk removal. The mechanical model of contact between grains and fibers in elliptical domain, and the mechanical model of single fiber cutting based on tensile fracture failure are established. Finally, considering the interface friction between the grinding wheel and the workpiece, the grinding force models under different lubrication conditions are established and verified by experiments. The model error is 14.73% under the optimal conditions. The results show that the lowest grinding force is obtained with the nano-enhanced bio-lubricant minimum quantity lubrication method, the normal and tangential forces are reduced by 22.93% and 55.79%, respectively, comparing with dry grinding.

Key words: grinding, CFRP, grinding force, minimum quantity lubrication, biological lubricant

CLC Number: