| 1. |
- Adolfsson, C, et al.
(författare)
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Cutting force model for multi-toothed cutting processes and force measurement equipment for face milling
- 1995
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Ingår i: International Journal of Machine Tools & Manufacture. - 0890-6955. ; 35:12, s. 1715-1728
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a mechanical cutting force model for multi-tooth cutting processes, where initial position errors in radial and axial direction, eccentricity and edge wear are taken into account. The cutting forces are presented for each individual cutting edge, and in a system of coordinates where one axis is parallel to the cutting speed vector at any instant. The process parameter cutting resistance, Cr is derived from the measured main cutting force FM. Cr should be regarded as a parameter since it is always increasing with decreasing values of theoretical chip thickness h1. A new way of measuring cutting forces in multi-tooth cutting processes is also presented. Eight cutting force components are measured on the tool close to each of the four cutting edges. The aroused signals are filtered, amplified, A/D-converted and put together in a serial stream for transmission through a hollow spindle via a fibre optic cable. The signals are sent from the rotating spindle to the frame of the machine over an air gap with Light Emitting Diodes. They are then demultiplexed, D/A-converted, and stored in a PC-based eight channel oscilloscope. With this measurement equipment it is possible to directly measure the cutting forces acting on each individual cutting edge.
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| 2. |
- Andersson, Carin, et al.
(författare)
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Bandsawing. Part I: cutting force model including effects of positional errors, tool dynamics and wear
- 2000
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Ingår i: International Journal of Machine Tools & Manufacture. - 0890-6955. ; 41:2, s. 227-236
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a mechanical cutting force model for bandsawing. The model describes the variation in cutting force between individual teeth and relates it to initial positional errors, tool dynamics and edge wear. Bandsawing is a multi-tooth cutting process, and the terminology of the cutting action is discussed and compared with other cutting processes. It will also be shown that the setting pattern and the preset feed govern the cutting data.
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| 3. |
- Andersson, Carin, et al.
(författare)
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Bandsawing. Part II: detecting positional errors, tool dynamics and wear by cutting force measurement
- 2000
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Ingår i: International Journal of Machine Tools & Manufacture. - 0890-6955. ; 41:2, s. 237-253
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a method for measuring individual cutting forces during bandsawing. Methods for detecting errors in cutting edge positions, tool dynamics during machining and geometry changes due to wear have also been developed. The experimental studies that we have conducted show that the cutting forces vary during the tool engagement. These variations in force were then quantified using a previously developed cutting force model for multi-tooth cutting processes including effects of positional errors, tool dynamics and wear.
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| 4. |
- Andersson, Carin
(författare)
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Bandsawing. Part III: stress analysis of saw tooth microgeometry
- 2001
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Ingår i: International Journal of Machine Tools & Manufacture. - 0890-6955. ; 41:2, s. 255-263
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a stress analysis of a saw tooth. The analysis aims to determine the stress distribution for various egde load and varying microgeometry. The analysis is performed on a three-dimensional finite element model representing the tip of a saw tooth. The 3D model makes it possible to model the load distribution and study stress distributions across the width of the teeth with a sufficient accuracy. The FEM calculations are based on experimental measurements of the individual cutting forces during bandsawing. The previous studies of nonuniform contact relationships on the rake face is used when modelling the load distribution.
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| 5. |
- Walter, M F, et al.
(författare)
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The connection between cutting and clamping forces in turning
- 1994
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Ingår i: International Journal of Machine Tools & Manufacture. - : Elsevier BV. - 0890-6955. ; 34:7, s. 991-1003
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Tidskriftsartikel (refereegranskat)abstract
- The chuck has, for a long time, been considered the weakest link of a lathe. This is mainly due to its two-fold connection, to the machine spindle on the one hand and to the workpiece on the other. An additional limitation of the chuck lies in the incomplete knowledge one has of the load it is exposed to during operation, which usually leads to a less than optimal machining process. Unless our understanding of the properties of clamping devices and of the effects of external loads is improved, the risk is great that this deficiency in our knowledge will be a limiting factor in the continuing development of machine tools [1]. The aim of this work has been to isolate and to investigate the factors that influence the necessary clamping forces when using jaw chucks. An extensive model development has been carried out towards a better understanding of the problem. The models thus developed have been analyzed as to their validity using the FEM and also through experimental studies. The present study has been limited to the processing of ring shaped, weak workpieces.
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| 6. |
- Zhou, Jinming, et al.
(författare)
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An approach for on-line cutting edge stress estimation
- 1994
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Ingår i: International Journal of Machine Tools & Manufacture. - : Elsevier BV. - 0890-6955. ; 34:5, s. 741-751
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Tidskriftsartikel (refereegranskat)abstract
- Cutting edge deteriorations are attributed to higher mechanical and thermal stresses working on it during metal cutting. However, the stress estimation is a difficult task, especially when on-line estimation is desired. This paper presents a new approach for cutting edge mechanical stress estimation and load simulation. The approach can be applied in the implementation of on-line stress estimation to the study of stress state at the cutting edge and the strategy of real-time edge deterioration monitoring. The approach is based upon cutting force measurement and cutting edge load analysis. The concept of load function and related stress are introduced to estimate stresses working on the cutting edge. With multiple regression, the related stresses can be estimated on-line, from which the actual stresses can be estimated. The method for two-dimensional stress estimation of a cutting edge is illustrated and the principle can also be applied to three-dimensional stress estimation of a cutting edge. The experimental results, obtained with a developed real-time monitoring system and their analysis with respect to cutting edge stress estimation and analysis under different processing phenomena are also reported.
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| 7. |
- Zhou, Jinming, et al.
(författare)
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Cutting Tool Fracture Prediction and Strength Evaluation by Stress Identification Part I: Stress Model
- 1997
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Ingår i: International Journal of Machine Tools & Manufacture. - 0890-6955. ; 37:12, s. 1691-1714
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Tidskriftsartikel (refereegranskat)abstract
- Cutting tool premature failure, caused by tool fracture and chipping, is a frequent problem in the metal cutting area. For a certain type of cutting tool, correctly identifying its load profile and property profile is very crucial for prediction of the tool premature failure. The most direct way to evaluate the load profile and property profile of a cutting tool is to identify the stress working on it. This paper presents a new method for identification of the maximum principal stress and maximum effective stress subjected to a cutting tool in a cutting process. The method consists of four steps: estimation of the contact load on the tool faces, calculation of the maximum related stresses with the FEM, modelling of maximum related stresses with an artificial neural network and, finally, identification of the maximum principal stress, σe, and maximum effective stress, σe, with the use of measured cutting forces or cutting parameters. The calculation of the contact load on the tool face is based on a simplification of the load distribution on the tool face. Part I of the paper will present this method and Part II will present the results of experimental studies.
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| 8. |
- Zhou, Jinming, et al.
(författare)
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Effect of chamfer angle on wear of PCBN cutting tool
- 2003
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Ingår i: International Journal of Machine Tools & Manufacture. - 0890-6955. ; 43:3, s. 301-305
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Tidskriftsartikel (refereegranskat)abstract
- In precision hard turning, a remaining problem is to minimise tool wear to maintain the accuracy of geometry and surface finish. Tool wear not only directly reduces the part geometry accuracy but also increases cutting forces drastically. The change in the cutting forces also causes instability in the tool motion, which results in more inaccuracy. PCBN cutting tools are often used in hard turning. However, they are still relatively expensive compared to ordinary carbide cutting tools. In order to attain sufficiently high production rates at minimum cost, increase of knowledge on cutting tool geometry is necessary. This article presents a study of the effect of chamfer angle on tool wear of PCBN cutting tool in the super finishing hard turning. The correlation between cutting force, tool wear and tool life were investigated. The optimised chamfer angle for PCBN cutting tool is suggested. Finally, the distribution of stresses and maximum principal stress working on the tool edge were calculated with the use of finite element method. (C) 2002 Elsevier Science Ltd. All rights reserved.
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| 9. |
- Geldart, M., et al.
(författare)
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A direct comparison of the machining performance of a variax 5 axis parallel kinetic machining centre with conventional 3 and 5 axis machine tools
- 2003
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Ingår i: International journal of machine tools & manufacture. - 0890-6955 .- 1879-2170. ; 43:11, s. 1107-1116
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Tidskriftsartikel (refereegranskat)abstract
- The current trend within the Tool and Die manufacturing sector is to machine components directly from hardened material using high speed 5-axis machining. This has been driven by the increasing requirements for cost competitiveness and lead-time reduction. Significant research effort has been applied to the optimisation of the process with factors such as tooling and machining strategies being considerably improved. However, the underlying structures of the machine tools used have remained unchanged and still consist of a serial kinematic chain. One of the standard justifications for the development of machines designed around parallel kinematic chains is that they should exhibit inherently greater stiffness, have higher axis accelerations and be capable of generating significantly higher cutting forces than conventional serial machines. This suggests that they should be ideally suited to the direct manufacture of tools and dies from hardened material. The comparison of different machine tool types is a complex and difficult process, particularly when their structures are fundamentally different. This paper describes an approach used to compare the performance of three very different types of machines. The technique uses two parameters; surface finish and geometric accuracy to assess the relative performance of different machine tools when cutting hardened material. The method is used to compare a serial kinematic 5-axis machining centre, a serial kinematic 3-axis machining centre and a parallel kinematic 6-axis machining centre. The results of the comparison are presented in this paper and show that all the machine tools performed to an equal standard for materials with a hardness of 54HRc but for very hard materials, 62HRc, the parallel kinematic machine out performed the serial machine tools.
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| 10. |
- Mackerle, Jaroslav
(författare)
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Finite element analysis and simulation of machining : An addendum A bibliography (1996-2002)
- 2003
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Ingår i: International journal of machine tools & manufacture. - 0890-6955 .- 1879-2170. ; 43:1, s. 103-114
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Tidskriftsartikel (refereegranskat)abstract
- This bibliography contains references to papers, conference proceedings and theses/dissertations dealing with machining simulated by the finite element methods that were published in 1996-2002. Three hundred and seventy-two references are listed. The paper is an addendum to the author's bibliography published in J Mater Process Technol 86 (1999) 17-44, which listed references on subjects published between 1976-1996.
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