Engineering MECHANICS, Vol. 14, 2007, No. 5, p. 1–13 1 INVERSE METHOD FOR CUTTING FORCES PARAMETERS EVALUATION Edouard Rivi` ere Lorph` evre, Enrico Filippi, Pierre Dehombreux* Simulation of the milling process is a widespread method to improve productivity in the machining process and several phenomena can be studied and controlled by this mean. All these methods need input parameters that characterize the interaction between the tool and the workpiece in order to evaluate the cutting forces. Many models exist, but the input parameters are often difficult to find out from intrinsic properties of the materials (Young’s modulus, yield strength, hardness, ... ). The aim of this article is to set out a simple and efficient method to compute cutting coefficient for two different cutting forces models from a single efforts measurement. The method is validated using both simulated and measured cutting forces. The adequacy is good and allows simulating the whole cutting process. Key words : milling, cutting forces, specific pressure, chatter vibration 1. Background Chatter vibration during machining is a well know issue which limits productivity. The regenerative effect has been widely studied and several simulation methods have been de- veloped, ranging from analytic approach (leading to the classical ‘stability lobes’ diagram) to dynamic simulation. The common point between all these methods is the fact that they all need information about the cutting force amplitude. The models based on the study of the microscopic phe- nomen [9] lead to a set of equations which are difficult to manipulate for simple computation. The common approach is thus to model cutting force in machining by mean of rela- tionship to technological ‘macroscopic’ parameters such as depth of cut or feed (see for example [6], [4], [8]). These empirical laws depend upon several parameters which are often difficult to correlate to physical properties of the material such as Young’s modulus, yield strength or hardness. Identification of those parameters from experimental analysis is thus a compulsory step to simulate machining process. 2. Cutting force measurement Most common sensors to measure cutting forces during machining are based on piezoelec- tric ceramics linked together to measure up to four components (forces along three directions and torque). Two main types have been developed in milling : rotating and stationary dy- namometers. Rotating dynamometers (Fig. 1) are composed of two parts: the sensor itself which acts as a toolholder interface between the tool and the spindle and a static part linked to the machine * E. R. Lorph` evre, E. Filippi, P. Dehombreux, Facult´ e Polytechnique de Mons, Service de G´ enie M´ ecanique, Rue du Joncquois 53, B-7000 Mons, Belgium