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Indexed by:会议论文

Date of Publication:2021-02-02

Volume:2017-August

Abstract:Carbon Fiber Reinforced Plastics (CFRPs) are a kind of hard-to-machine material. They are vulnerable to the generation of delamination, burring, fiber-matrix debonding and etc. during the drilling process. The drilling induced delamination has been researched in some previous studies. Whereas, the burring, fiber-matrix debonding that critical to the structural strength of the workpiece and the assembly of the components are rarely studied. The objective of this paper is to study the burrs induced in the drilling of CFRP laminates. Considering the numerical simulation has great advantages for the study of the damage induced by CFRP drilling, a three-dimensional finite element model was developed to simulate the drilling of multi-directional CFRPs. As the CFRPs consist of fiber phase and matrix phase on microscopic scale and exhibit anisotropy and stacking features on macroscopic scale, the model was developed on both of the two scales. In this model, part of the workpiece contains fiber phase and matrix phase to simulate the CFRP drilling on microscopic scale. (It should be noted that, the fiber phase is not representing a single fiber, but a bundle of fibers due to computational constraints.) And the other part was modelled based on the Equivalent Homogeneous Material (EHM) assumption to simulate the CFRP drilling on macroscopic scale. Meanwhile, the size of the elements in different parts were unequal, and a balance between accuracy and computational cost was achieved through refining the element sizes. Also, different constitutive laws, failure initiation criteria and damage evolution laws were implemented to replicate the interrelated cutting behaviour of different phases. The drilling process of the multi-directional CFRPs was simulated by this model, and the sizes of the induced burrs at the hole wall and outlet of the hole were compared. In addition, the simulation results were validated by experiments. © 2017 International Committee on Composite Materials. All rights reserved.