1,721,031 research outputs found
Formatura incrementale: una cella robotizzata integrata per produzione e controllo qualità
No full text
Incremental forming: an integrated robotized cell for production and quality control
No full textThe present work proposes the integration of a incremental forming robotised system with an optical measurement device (robotised too) formerly developed for quality control purposes of processes and products.
A parallel kinematics robot moves a spherical punch according to a predefined path, deforming a gridded sheet metal that is scanned by a couple of cameras moved by a second robot.
As a result of the post-processing of the acquired images, accordingly to the so called grid method, the strain distribution can be computed, and the quality of the forming process can be assessed.
The system is completed by a projector and four fixed cameras, that permit to evaluate the final shapeof the formed part by means of the fringe projection and phase shift techniques
Effect of the strain-rate on the damage evolution in stainless steel and aluminum alloys
No full text
Material Characterization at High Strain Rate by Hopkinson Bar Tests and Finite Element Optimization
No full textIn the presentwork, dynamic tests have been performed on AISI 1018CRsteel specimens by means of a split Hopkinson pressure bar (SHPB). The standardSHPBarrangement has been modified in order to allowrunning tensile tests avoiding spurious and misleading effects due towave dispersion,
specimen inertia and mechanical impedance mismatch in the clamping region.However, engineering stress–strain curves obtained from experimental tests are far from representing true material properties because of several phenomena that must be taken into account: the strain rate is not constant
during the test, the specimen undergoes remarkable necking, so stress and strain distributions are largely non-uniform, and the temperature increases because of plastic work. Experimental data have been post-processed using a finite element-based optimization procedure where the specimen
dynamic deformation is reproduced. Optimal sets of material constants for different constitutive models (Johnson–Cook, Zerilli–Armstrong and others) have been computed by fitting, in a least mean square sense, the numerical and experimental load–displacement curves
Analisi dinamica di una pala di turbomacchina assiale. Procedura di verifica a fatica ad alto numero di cicli
No full text- …
