Delamination prediction in orthogonal machining of carbon long fiber-reinforced polymer composites

Abstract

Machining processes of composites are common operations in industry involving elevated risk of damage generation in the workpiece. Long fiber reinforced polymer composites used in high-responsibility applications require safety machining operations guaranteeing workpiece integrity. Modeling techniques would help in the improvement of machining processes definition; however, they are still poorly developed for composites. The aim of this paper is advancing in the prediction of damage mechanisms involved during cutting, including out-of-plane failure causing delamination. Only few works have focused on three-dimensional simulation of cutting; however, this approach is required for accurate reproduction of the complex geometries of tool and workpiece during cutting processes. On the other hand, cohesive interactions have proved its ability to simulate out-of-plane failure of composites under dynamic loads, as impact events. However, this interlaminar interaction has not been used up to date to model out-of-plane failure induced during chip removal. In this paper, both a classical damage model and cohesive interactions are implemented in a three-dimensional model based on finite elements, in order to analyze intralaminar and interlaminar damage generation in the simplified case of orthogonal cutting of carbon LFRP composite. More realistic damage predictions using cohesive interactions were observed. The strong influence of the stacking sequence on interlaminar damage has been demonstrated.

Numerical analysis of the ballistic behaviour of Kevlar® composite under impact of double-nosed stepped cylindrical projectiles

“…The parameters in Table 3 are the following: 11 , 22 , and 33 , are the stresses in longitudinal, transverse and through-thethickness direction, respectively; 12 , 23 , and 13 , are the shear stresses; X T1 and X T2 are the tensile strengths in warp and weft directions; Z R is the tensile strength in the through-the-thickness direction; S L is the longitudinal shear strength; S T is the transverse shear strength. Failure occurs when any damage variable (d ij ) reaches the value 1.…”

Modelling thermal effects in machining of carbon fiber reinforced polymer composites

“…12,22 The validation of the model was presented in previous works of the authors. 16,17 Delamination was modelled using cohesive interactions between plies able to reproduce out of plane failure. 17 The cohesive interaction allows reproducing delamination propagation as a fracture mechanics phenomenon, instead of stress-based models (as it is the case of Hou criteria).…”

“…16,17 Delamination was modelled using cohesive interactions between plies able to reproduce out of plane failure. 17 The cohesive interaction allows reproducing delamination propagation as a fracture mechanics phenomenon, instead of stress-based models (as it is the case of Hou criteria). The surface-based cohesive interaction available in ABAQUS was used to predict delaminated area.…”

“…17 The average temperature along the cutting edge was compared with that observed in ref. [6] shown in Figure 2.…”

“…The aim of this paper was to explore the ability of numerical modelling based on finite element for simulation of temperature enhancement during cutting. The model of orthogonal cutting, previously developed and validated, 16,17 has been modified in order to account for thermal effects. The model is used for prediction of intralaminar damage, delamination, and also thermal damage accounted in terms of temperature level beneath the machined surface.…”