Numerical Methods for the Simulation of Segmented Chips and Experimental Validation in Machining of Ti-6al-4v

Abstract

The simulation of machining processes holds the opportunity for process improvement on many levels. Possible benefits that can be derived from accurate representations of the real processes on the tool from simulations include a prediction of tool wear, the shape of the chips produced, the forces, frictions and temperatures that arise and the residual stresses in the workpiece. These predictions can be used to improve the process in terms of its economic and ecological behaviour: Increasing the service life of the tools used through an improved understanding of the tool-workpiece interaction. The finite element method (FEM), among others, has emerged as a common method for simulating these processes. When simulating machining processes using FEM, a major challenge is to avoid or compensate for the mesh distortions caused by the massive, fast-moving deformation processes, but at the same time to allow the mesh to be discretised in some way to ensure chip removal. To this end, various approaches will be presented in the course of this work and the mesh-based approaches will be explored in depth. Among other things, a remeshing approach for these investigations was developed. The machining of TI6AL4V is used to illustrate these approaches, as its tendency to form segmented chips is particularly challenging to model.

Development of a Multi-Sensor Concept for Real-Time Temperature Measurement at the Cutting Insert of a Single-Lip Deep Hole Drilling Tool

“…For the simulation of the drilling process, the CEL method was used to calculate the problem. This simulation method has already been successfully used for machining simulations [8,11], mostly an orthogonal cutting process, and offers many advantages compared to an explicit Lagrangian simulation when dealing with problems with large deformations. The material 42CrMo4+QT (AISI 4140) was used for the investigations.…”

“…Among other things, a sensory tool was used for the temperature measurements, with three PTC sensors integrated here under the cutting insert [6]. In order to investigate the temperature in a two-dimensional state, orthogonal cuts were performed presenting experimental and simulational chip formation, frictional impacts and the resulting temperatures [7,8]. To study the SLD process, several investigations were carried out.…”