Dystamill: a framework dedicated to the dynamic simulation of milling operations for stability assessment

Abstract

Dystamill is an open-source framework, available for free on the Internet, that allows its user to perform milling simulations from a model of the machine tool dynamics, a description of the cutting tool, a representation of the workpiece and a cutting force model. First developed as a program to study the stability of milling operations, the C++ code was ported into a library so that it can now be coupled with a multi-physics engine or used standalone. Restricted to 2D $\frac {1}{2}$ cases, achievable cutting operations include contouring, slotting and face or pocket milling since the tool only moves in a plane perpendicular to its revolution axis. Dystamill permits computing the machining forces applied on the tool and generating the geometry of the machined workpiece. Achieving dynamic simulations in a row for various cutting conditions enables determining the chatter stability lobes needed to choose optimal cutting parameters. The C++ library is composed of 12 modules interacting with each other to model the milling studied case, involving namely a modelling of the tool and the machined surface, a cutting force model and a representation of the system dynamics through a modal model. It is completed with a GUI that generates an input file for Dystamill while the post process of the results can be carried out by Matlab™. Born from a Ph.D. thesis, Dystamill was tested and validated on numerous test cases from the literature and real experiments. This paper is an opportunity to shed light on the functions and algorithms of Dystamill. In the hope that it will be useful for users, this document presents the Dystamill library, namely its modules are described from a technical point of view. An early example is built up and validated through real measurements. Finally, the capabilities of Dystamill are illustrated by comprehensive examples leading to the chatter stability lobes.