Wyniki wyszukiwania - BazTech

1

Research and modeling workpiece edge formation process during orthogonal cutting

Preś P., Skoczyński W., Jaśkiewicz K.

Archives of Civil and Mechanical Engineering

|

2014

|

Vol. 14, no. 4

622--635

EN

This paper presented the study of the phenomenon of the material deformation at the edge of the workpiece during the orthogonal cutting of steel C45E and two-dimensional model of this process, developed with using the Finite Element Method. Based on the user's procedure VUMAT, the Johnson–Cook's law and Ductile Damage model were applied to describe the machined material. An extensive verification of the modeled process was performed. The phenomenon of material deformation at the edge of the workpiece during the actual orthogonal cutting process was recorded using a high speed camera. The courses of the real phenomenon with the modeled one were compared. The components of the resultant cutting force were measured during orthogonal cutting for different machining parameters. The measurement results were compared with the values of the components of the resultant cutting force calculated on the basis of numerical simulation. The studies on the burr formation mechanism were performed. The contactless measurement of selected geometric features of the burr was performed. The results of measurements of the selected geometric features of burrs obtained from the experiment were compared with those compiled based on FEM simulation.

2

Powstawanie zadziorów przy frezowaniu współbieżnym i przeciwbieżnym stopu AlSi10Mg

Falkowicz K., Kuczmaszewski J.

Przegląd Mechaniczny

|

2012

|

nr 9

23-27

PL

Operacje usuwania zadziorów są dość kosztowne, dlatego też znajomość tworzenia się zadziorów pozwala na uwypuklenie istotności tego zagadnienia w świetle ogólnie rozumianej obróbki skrawaniem. W artykule przedstawiony został? mechanizm formowania si´ zadziorów w procesie frezowania czołowego stopu AlSi10Mg. Zbadano również wpływ poszczególnych parametrów obróbki na wielkość powstających zadziorów.

EN

Since deburring is a costly and non-value-adding operation, the understanding and control of burr formation is a research topic with high relevance to industrial applications. The purpose of this paper was to study the burr formation mechanisms in face milling process of aluminum alloy AlSi10Mg, and to investigate the influence of machining parameters on burr formation in face milling.

3

Modelled phenomenon of burr formation during machining

Preś P., Skoczyński W.

Journal of KONES

|

2012

|

Vol. 19, No. 1

333-338

EN

A model of burr formation on the edge of the workpiece in the course of machining is presented. The material being machined, the cutting tool and the machining parameters were modelled. Material properties and type of its deformations have been modelled with the use of a constitutive Johnson - Cook model. Material damage initiation criteria and associated damage evolution have been modelled with the use of the ductile damage and the Johnson- Cook damage initiation criterion. Simulations of the machining process for different depths of cut were carried out. The real burr formation presented by Hashimura was compared with the modelled one. The influence of the cutting parameters on the form and size of burr has been analysed. Calculations have been realised utilising finite element method with the use of nonlinear analysis in ABAQUS/Explicit environment. Based on simulation results, the assessment of the form and size of burr has been made. Burr height was used to evaluate its size, which was derived according to ISO 13715 standard. The goal was to obtain a model that reliably reflects the behaviour of material during machining, with particular emphasis on supporting the creation of cutting phenomenon of burr formation. The results of simulation and computational analysis confirmed that the model reflects the real behaviour of the material.

4

On burr height estimation based on axial drilling force

Sokołowski A.

Journal of Achievements in Materials and Manufacturing Engineering

|

2010

|

Vol. 43, nr 2

734--742

EN

Purpose: The main goal of the research is to build a model of relationship between burr height created during drilling operation and signal representing axial drilling force. Such a model can be applied in diagnostic system for on-line estimation of bur height. Design/methodology/approach: The first applied approach is based on a step by step procedure in which several statistical models were built. The second one is based on specific features of artificial intelligence methods. The artificial neural networks serve as a tool for data selection and integration while the fuzzy logic systems are applied for data integration, only. Findings: The developed algorithm for processing axial drilling force allowed constraining the noise inherent to the drilling process and emphasising the information that could be useful for building considered model. The impact of the properly conducted data selection has been emphasised. Also, importance of providing information represented with axial drilling force has revealed. Research limitations/implications: The developed models need to be checked or improved for practical implementation. Such improvement can be done by introducing other signal features or other cutting parameters as model inputs. Also, analysis of other signals that can be measured during drilling is assumed as a future work. Practical implications: The conducted research reconfirmed possibility of on-line diagnostics of bur height during drilling. Several parameters necessary for such diagnostics have been estimated. This suggests continuing the research in order to design a system that could be applied in industrial conditions. Originality/value: The proposed approach is not a typical since analytical models, FEM models or models basing only on cutting process parameters have been considered, mainly. Such models are limited to two dimensional machining, usually. Besides, application of artificial intelligence methods for data selection and integration points at novelty of the research conducted.