Zoubeir Bouaziz

Numerical and Experimental Approach in Assisted Cryogenic Machining

Understanding of local mechanisms chip forming during machining by removal of material is difficult, to this end; a cutting finite element modelling is required. This study aims initially to model orthogonal cutting of Ti17 titanium alloy in dry and cryogenic machining and in a second time to study the influence of the application of cryogen during machining on temperature fields and cutting forces in numerical simulation. An experimental study was also conducted to determine the mode of tool wear and the evolution of flank wear.

Compensation of a ball end tool trajectory in complex surface milling

This work is consecrated to the minimising of machining errors based on a method for the compensation of the trajectory to be machined in hemispherical milling. This compensation is found to be necessary because of the tool deflection due to the cutting forces. In order to remedy to the machining errors, caused by this deflection, a compensation method has been proposed. The latter is inspired from the mirror method, since the compensated position is going to be determined as being the trajectory reflection, deviated onto the mirror. The advantage of this proposed method is that it takes into account the three deflections dx, dyand dz, respectively to the directions X, Y and Z. After that, two-parallel machinings, separated by a groove and achieved absolutely in the same conditions and with the same tool, are carried out, on the same complex part. The first machining is with compensation, but the second is without compensation. The coordinates of the two obtained surfaces are recorded by a 3D measuring machine. The comparison of the two-surfaces shows the presence of an important correction of the tool trajectory, and reveals a similarity between the part obtained by simulation and the one conceived in CAM.

COST EVALUATION FOR WELDING PROCESS BY USING PREPARING FEATURES

Abstract This paper presents an approach for costing of weld preparation. The approach introduces the concept of preparing feature for the preparation of the welding joint edges. A generation of manufacturing process method is detailed. This method use production rules and respects the geometrical and technological parameters. A cost function uses an analytical method elaborated to formulate the time for weld preparation according to the different parameters of preparing feature. The estimating is based upon an evaluation of machine implementation, labour and consumable costs. At last, and to show the developed method interested and the efficiency of the model, we have treated an example of stiffened plate.