0000000000341624
AUTHOR
A. Masnata
In-process tool-failure detection by means of AR models
The present paper proposes a cutting tool breaking and chipping detection system for continuous and interrupted cutting, based on the analysis of the cutting force componentsFx andFy. A multifactorial experimental design has been carried out, to take account of the variability of the force signal. An adaptive signal processing algorithm is proposed, which detects catastrophic failure when at least one component deviates outside an estimated oscillation band for a time duration longer than a prefixed interval. The algorithm has been implemented on a four-microprocessor transputer board. Several tests confirmed the validity of the approach for detecting breaking and chipping phenomena in a fe…
Influence of Feed on Tool Life of Sintered Carbide in Interrupted Cutting
The paper examines the influence of feed on the mean life of sintered carbide inserts in turning UNI 48S5 steel in interrupted cutting conditions.
THE INFLUENCE OF TOOL STIFFNESS OF THE LIFETIME OF THE INSERTS IN INTERRUPTED CUTTING OPERATIONS
ABSTRACT In the present paper the influence exerted by the stiffness of the tool-workpiece system under working conditions on tool life up to the fracture of carbide inserts in interrupted cutting is investigated. It is shown how, with the increase in compliance of the system, there is a corresponding increase in the average tool life of the insert which is greater the lesser the cutting speed. The results of tests carried out indicate as a possible cause the amount of damage evident in the successive phase of tool engagement with the workpiece. It was observed how, in this phase, the tool, vibrating at the same rate as the toolholder produces alternations in the cutting force. This effect …
HEURISTIC PROCEDURES FOR GROUP SCHEDULING
ABSTRACT The group scheduling problem is investigated, solving numerous small and large sized examples with eight sequencing algorithms. A new approach, basically consisting in the definition of real machines' idles for each group, utilizing allowed shifting of non critical activities, is proposed. Moreover the CDS multi-shot algorithm is extended to group scheduling.
Crack identification in a beam by measure of the response to white noise
The aim of this paper is to inspect the vibrational response of a beam with an edge non-propagating crack by means of stochastic analysis, in order to detect the presence and the location of structural damage. The non- linear behavior of the beam due to the opening and closing of the crack is fully exploited. The non-linearity measure is based on the response evaluation of the beam subjected to a white noise process. Both numerical and experimental investigations regarding a cantilever beam with a crack are reported in the paper.
Central Bursting Defects in Drawing and Extrusion: Numerical and Ultrasonic Evaluation
Abstract A new approach for the prediction of central bursting defects in extrusion and drawing is proposed: a finite element analysis of the processes has been carried out, and the obtained results have been elaborated by means of a post-processor, which, employing a proper ductile fracture criterion, is able to suggest if and where the central burst occur. An ultrasonic control system able to detect the insurgence of defects with a resolution of 0.2 mm. has been setup in order to verify the predictive capability of the model. The experimental results show a good agreement with the numerical predictions confirming the effectiveness of the proposed approach, whose industrial application app…