Numerical simulation of chip formation during edge cutting machining of 3D orthogonal woven fiber-reinforced composite workpiece. Part 2: geometric and physical modeling

This publication represents a continuation of the first part and is specifically focused on the modeling of the machining process of a composite workpiece. Due to the fact that edge cutting machining is more commonly used to produce precise parts made of fiber-reinforced composite (FRC) with three-dimensional woven orthogonal structure, it is advisable to predict the quality of machined surfaces using numerical computer modeling. Appropriate numerical methods of geometric modeling of tools and the composite workpieces, including voxel modeling, should be used to create numerical physical models of such machining. Voxel modeling, in contrast to analytical geometry in space, is absolutely stable for describing surfaces of any degree of complexity. Since all real objects, including composite fibers, have surface roughness, voxel models are an effective means for composite material modeling. In addition, voxels, as particles, are geometric analogues of physical modeling particles used for the method of smoothed particle hydrodynamics (SPH), which is increasingly used to simulate edge tool machining. Based on this, the paper considers generation of a voxel model of a workpiece made of three-dimensional woven FRC, developing an SPH model of the composite using voxel model, and calculating the stress-strain state of the cutting zone during machining. The specified model of the machining process uses the material models and material parameters selected in the first part of the presented article. The Johnson-Cook model is used for metal composites description. The selection of model parameters including parameters of the fiber-matrix boundary layer was presented the first part of the publication. The results of initial modeling of a homogeneous material workpiece machining produced an encouraging result. Subsequent modeling of a composite workpiece machining showed differences in the stress-strain state of its cutting zone from such a zone for a homogeneous workpiece, including increased chip sizes in the moment when the tool wedge leaves the workpiece. Other differences were also found for these two workpiece kinds, which must be taken into account for proper selection of the parameters of a technological operation and elements of a technological system. Along with this, the publication shows that these researches require intensive further study. Refinement of the model of matrix-fiber boundary layer material is a particularly important task.