1,721,052 research outputs found
Influence of Tool Geometry and Cutting Parameters on the Machinability of SiC-Aluminium Composites
No full textDamage analysis in mechanical clinching: Experimental and numerical study
No full textA numerical model describing the evolution of ductile damage was developed to predict the onset of fracture during the clinch joining of thin aluminium AA6082-T6 sheets. The damage model was calibrated and validated using instrumented punch-out tests in order to increase the reliability and robustness of the damage parameter. An inverse analysis was performed (by varying the damage parameter) by minimizing the difference between the experimental and numerical prediction concerning the load-stroke curves and the geometries of punched cross-sections. Then, a numerical model of mechanical clinching using the damage parameter was developed and compared with experimental clinched connections. The results show that the model enables the onset of cracks in critical regions to be predicted. The critical regions are the punch-sided sheet neck and die-sided sheet bulge. The established numerical model of clinching provides a viable means for optimizing the geometry of the clinching tools so as to improve the mechanical behaviour of the joints (by maximizing the undercut and reducing the neck thinning) other than preventing the onset of cracks on the joints
Experimental investigation on the laser bending of steel sheets by means of diode laser
No full textLaser bending is a new technique to deform sheets that offers the advantage of requiring no external forces,
thus reducing cost and increasing flexibility. The present work is focused on the laser forming of steel sheets
carried out by means of a diode laser. The influence of process parameters, such as laser beam power and
scanning speed as well as the sheet thickness, on the bending angle has been taken into account. The
investigation has also analysed the effect of sheet rolling direction on the bending process. Experimental
data have been compared with those obtained by analytical models proposed in literature
Assessment of Twist Drill Temperature in Metal Matrix Composites Drilling
No full textIn this paper a new experimental approach was developed to evaluate twist drill temperature in drilling process of
metal matrix composites. Drill temperatures were measured by inserting k-thermocouples, which were welded in
different zones of the tool grooves, and by using an infrared pyrometer. A radiofrequency transmission system
was realised in order to transmit signals obtained by the thermocouples to a data acquisition system. The
workpiece material was a composite with an aluminium matrix reinforced with silicon carbide powders. The
experimental tests were carried out in order to assess the influence of drilling parameters on tool temperature and
cutting force
Geometrical characterization of low carbon steel wires drawn with flat idle rolls
No full textThis paper deals with a geometrical characterization of low carbon steel wires drawn with flat idle rolls, namely, Roll Drawing (RD). Despite conventional wire drawing, in roll drawing, the wire is not completely in contact with the rolls, therefore material flow evolution requires further attention. Finite element simulations, under various loading conditions, were carried out to address the material flow to the main process parame-ters, e.g., wire diameter, roll radius, roll gap, material flow stress and friction conditions. Results from numeri-cal data were used to develop a neural network which allows to predict the cross sectional shape of proc-essed wires with roll drawing avoiding further numerical investigation. Material lateral spreading and radius of curvature of worked products were measured on the neural network to compare with the finite element data. Through such comparison, the validity of the proposed neural network was verified. The material flow of sub-sequent flat-round pass needed to produce a finished wire is addressed in a subsequent investigation
The Influence of Shape and Content of Reinforcement on Grindability of Metal Matrix Composites
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Delamination Reduction during Drilling of AFRPs Composites by using an Adaptive Controller with Constraint
No full textA Monitoring System for Metal Matrix Composites Grinding Based on a no Contact Capacitive Sensor
No full textA capacitive sensor for in-process evaluation of grinding wheel cutting ability during metal matrix composites machining is proposed. The capacitive system is based on a sensor formed by a conducting surface that is a capacitor plate with an insulating medium, while the second plate is the grinding wheel. The sensor has been characterised by static tests, measuring the capacity at the grinding wheel surface conditions. Dynamic tests have been carried out on a horizontal spindle surface grinder equipped with a two-components piezoelectric dynamometer, clamped on the grinding table. The capacitive sensor has been interfaced with a data acquisition system and placed on the head of the machine tool. Assessment of grinding wheel wear has been obtained by measuring on-line cutting force components and flat area percentage on tool surface
A Comparison Between Conventional Abrasives and Superabrasives in Grinding of SiC-Aluminium Composites
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