Ferdinando Salvatore

Numerical simulation and analytical modelling of ploughing and elastic phenomena during machining processes

The present work deals with the presentation of an analytical methodology allowing the modelling of chip formation. For that, a ‘phenomena split method’, based on assuming that the material removal is the contribution of three phenomena, ploughing, spring back and ‘pure cut’, is developed. In particular, the elaboration of analytical sub-model of ploughing and spring back is presented in detail. FEM simulations and experimental data concerning temperatures and forces evolution are exploited to calibrate and verify the proposed analytical model dealing with ‘ploughing and spring back’. It is possible with this model to understand the physics of chip formation, and model lateral burrs and elastic phenomena under the tool and at the rear (spring back). The cutting radius contribution is analysed, which is important to the understanding of the tool wear and the residual stresses in the finished work-piece.

Numerical and experimental study of residual stress induced by machining process

Machining processes are widely used in different industries to cut different engineering parts. Usually, optimisation of these processes is made by experimental or numerical simulations. In particular, surface integrity modelling of the final piece is very important for the fatigue behaviour. In this paper modelling of the residual stresses in the fresh workpiece produced is studied. In particular finite element modelling using ABAQUS Explicit is employed in order to simulate chip formation and an implicit static calculation is made to have spring back in the workpiece after cooling. Orthogonal cutting process is chosen because it is simple and practice and different calculations method and numerical options are employed in order to replicate as well as possible physics during the process. In particular it is taken into account the cutting radius of the tool and the boundaries conditions of the workpiece. The setting of the numerical model is executed regarding the experimental conditions used. In the experimental section a complete study of the influence of the residual stresses by process variables (feed, cutting speed) is presented.

Analytical and numerical study of the separation line between chip and work-piece during cutting processes

In manufacturing industry, a high interest in analytical methods are usually researched because there are very practicable to use but those methods do not take into account all the aspects of the contact between the work material and the tool. In particular, ploughing and spring back are usually not considered, which is pertinent for small cutting edge radius but not for bigger ones (used tools). In reality, a part of the work-piece becomes chip and another part slides under the tool (elastic phenomena) and laterally (burrs). A separation line appears between those phenomena and the material under this surface stays in the work-piece during tool action. In this zone, elastic and plastic aspects induce temperature and spring back at the rear of the tool, which is important for residual stresses in the work-piece after cooling. In this paper, a simple analytical formulation is proposed in order to model the separation surface value. This analytical approach is fitted with 2D and 3D numerical simulations and verified with experimental forces and burr measurement.

Analytical Model of Chip Formation in Case of Orthogonal Cutting Processes

The present work deals with the presentation of analytical methodology allowing the modeling of chip formation. For that a “decomposition approach”, based on assuming that the material removal is the summation of two contributions, ploughing and pure cut was adopted. Moreover, this analytical model was calibrated by a finite element model and experimental data in terms of temperature and applied forces evolutions. The global aim is to propose to the industrial community, an efficient rapid-execution analytical model concerning the material removal in the case of an orthogonal cutting process.

ANALYTICAL MODEL FOR CHIP FORMATION IN CASE OF ORTHOGONAL MACHINING PROCESS

The present work deals with the presentation of analytical methodology allowing the modelling of chip formation. For that a “decomposition approach”, based on assuming that the material removal is the summation of two contributions: ploughing and pure cut was adopted. Moreover, this analytical model was calibrated by a finite element model and experimental data in terms of temperature and forces evolutions. The global aim is to propose to the industrial community, an efficient rapid‐execution analytical model concerning the material removal in the case of an orthogonal cutting process.