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Numerical modeling of orthogonal cutting of carbon fibre reinforced polymer composites

University of British Columbia

The focus of this study is on the orthogonal cutting of fibre reinforced composites. A thorough review of the literature is presented in both experimental and numerical work that has thus far been conducted. It is found that in orthogonal cutting of composites, cutting forces, chip formation mechanism and the extent of damage below the cutting plane are highly dependent on the fibre orientation. With fibre orientation increasing from 0° to 90°, cutting forces tend to increase and chips become more dust-like. Two modeling approaches are most commonly adopted for the prediction of force and chip formation, namely the micro-mechanical and the macro-mechanical approach; in the former, the fibre and the matrix are modeled as separate phases and their interface is defined by a traction-separation law. In the latter, the composite is represented by an anisotropic equivalent homogeneous material. It is shown that the numerical predictions are in good agreement with experimental results. With ABAQUS being the most commonly used tool for modeling of composite orthogonal cutting, a two-dimensional macro-mechanical model for cutting of CFRP was created in ABAQUS using Hashin’s damage model. The cutting forces were predicted for fibre orientations of 0°, 30°, 45°, 60°, 90° and 135°. Good prediction of cutting forces with the available experimental data in the literature was obtained. The model however fails to predict the complete chip formation mechanism due to limitations in the material model. A similar model was developed in LS-Dyna using MAT_054 for composites. The cutting forces were found to be sensitive to the damage input parameters, mainly the strain-to-failure of the elements. However, the complete chip formation and chip release was captured in this model which correlated well with the experimental observations. It is suggested that for improved modeling capability, better understanding of the damage behaviour of FRP, especially at the micro-scale is needed. Also, the existing work is found to be limited to orthogonal cutting and drilling separately; it is however worth looking into both items in one study and linking the two processes through a geometric transformation which is the established framework in metal machining.

Text

2016-07-08

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/58401

Civil Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/